Kyiv on Friday reported a massive cyberattack on key government websites as tensions between Russia and the West over Ukraine escalate following several rounds of unsuccessful talks.

The Education Ministry said on Facebook that its website was down due to a "global (cyber) attack" that had taken place overnight. Other websites that were down included that of the Cabinet and the foreign and emergencies ministries.

According to the Ukrainskaya Pravda newspaper, websites of the country's Cabinet, seven ministries, the Treasury, the National Emergency Service and the state services website, where Ukrainians' electronic passports and vaccination certificates are stored, were unavailable as a result of the hack. No one immediately claimed responsibility for the attack.

The Foreign Ministry website temporarily displayed a message in Ukrainian, Russian and Polish that appeared to suggest the attack was in response to Ukraine's pro-Western stance. It also claimed that all personal information of the country's residents is uploaded to the "public network" and all data on computers will allegedly be destroyed without the possibility of recovery.

"Ukrainians! All your personal data has been uploaded to the public network. All data on the computer was destroyed and is impossible to restore. All information about you has become public, be afraid and expect the worst. This is for your past, present and future, for Volyn, OUN, UPA, Galitsia, Polesye and for historical lands," it said, referring to ultra-nationalist organizations and regions of Ukraine.

The Education Ministry said that authorities – including the SBU security service and cyberpolice – were working to address the issue.

The content of Ukraine's government websites was not changed during the recent cyberattack and no personal data was leaked, the government said Friday. It added in a statement that a number of other government websites had been suspended to prevent the attack from spreading to other resources but most of the affected state resources had already been restored.

"It's too early to draw conclusions, but there is a long record of Russian assaults against Ukraine in the past," Foreign Ministry spokesperson Oleh Nikolenko said, answering a question on who is behind the attack. A top Ukrainian security official told Reuters: "All subjects of cyber security were aware of such possible provocations by the Russian Federation. Therefore, the response to these incidents is carried out as usual."

On Dec. 21, the New York Times reported that the United States and Britain had secretly sent a team of cybersecurity experts to Ukraine. It claimed that the West wants to help Kyiv to be prepared for alleged cyberattacks.

European Union foreign policy chief Josep Borrell condemned on Friday the attack and said the EU's political and security committee would convene for an urgent meeting on the attack, which he added "merits condemnation."

"We are going to mobilize all our resources to help Ukraine to tackle this cyber attack. Sadly, we knew it could happen," Borrell told reporters at an EU foreign ministers meeting in the western French city of Brest. "It's difficult to say (who is behind it). I can't blame anybody as I have no proof, but we can imagine."

Stalling diplomacy

The hacking of government sites comes as tensions between Russia and the West soar over Ukraine, a strategic ex-Soviet country. This week the United States and its NATO allies held talks with Russia in an attempt to ease tensions, but all three rounds of negotiations – in Geneva, Brussels and Vienna – proved unsuccessful.

In Vienna, talks with Russia at the Organization for Security and Cooperation in Europe (OSCE) ended on Thursday in a stark warning from diplomats about a possible military escalation between European nations and Russia.

Russia raised the stakes Friday when the country's Foreign Minister Sergey Lavrov described Moscow's demands that NATO neither expand nor deploy forces to Ukraine and other ex-Soviet nations as essential for the progress of diplomatic efforts to defuse soaring tensions over Ukraine. He argued that the deployment of NATO forces and weapons near Russia's borders poses a security challenge that must be addressed immediately.

"We have run out of patience," Lavrov said at a news conference. "The West has been driven by hubris and has exacerbated tensions in violation of its obligations and common sense."

Lavrov said that Russia expects Washington and NATO to provide a written response to its demands next week.

On Thursday, Deputy Foreign Minister Sergei Ryabkov refused to rule out a military deployment to Cuba and Venezuela if tensions with the United States rise. Ryabkov said he could "neither confirm nor exclude" the possibility of Russia sending military assets to Latin America if the U.S. and its allies do not curtail their military activities on Russia's doorstep.

"It all depends on the action by our U.S. counterparts," the minister said in an interview with Russian television network RTVI, citing Russian President Vladimir Putin’s warning that Moscow could take unspecified "military-technical measures" if the U.S. and its allies fail to heed its demands.

U.S. national security adviser Jake Sullivan dismissed the statements about a possible Russian deployment to Cuba and Venezuela as "bluster in the public commentary."

Ryabkov led a Russian delegation in talks with the U.S. on Monday. The negotiations in Geneva and a related NATO-Russia meeting in Brussels took place in response to a significant Russian troop buildup near Ukraine that the West fears might be a prelude to an invasion.

Russia, which annexed Ukraine's Crimea Peninsula in 2014, has denied having plans to attack the neighboring country. The Kremlin reacted to the suggestion by accusing NATO of threatening its territory and demanding that the military alliance never embrace Ukraine or any other ex-Soviet nations as new members.

Washington and its allies firmly rejected the demand this week as a nonstarter, but the NATO and Russian delegations agreed to leave the door open to further talks on arms control and other issues intended to reduce the potential for hostilities.

Speaking to reporters in Washington, Sullivan said that "allied unity and transatlantic solidarity were on full display and they remain on full display" during this week's talks with Russia, which he described as "frank and direct."

"We stuck to our core premise of reciprocity," the national security adviser said. "We were firm in our principles and clear about those areas where we can make progress and those areas that are non-starter."

Sullivan noted that no further talks have been scheduled, but "we’re prepared to continue with diplomacy to advance security and stability in the Euro-Atlantic."

"We’re equally prepared if Russia chooses a different path," he added. "We continue to coordinate intensively with partners on severe economic measures in response to a further Russian invasion of Ukraine."

Asked about Ryabkov keeping the door open to basing troops and equipment in Latin America, Sullivan responded: "I’m not going to respond to bluster in the public commentary."

He noted that the issue was not raised during this week’s talks and added that "if Russia were to move in that direction, we would deal with it decisively."

Ryabkov last month compared the current tensions over Ukraine with the 1962 Cuban Missile Crisis – when the Soviet Union deployed missiles to Cuba and the U.S. imposed a naval blockade of the island.

That crisis ended after U.S. President John F. Kennedy and Soviet leader Nikita Khrushchev agreed that Moscow would withdraw its missiles in exchange for Washington’s pledge not to invade Cuba and the removal of U.S. missiles from Turkey.

Putin, in seeking to curtail the West's military activity in Eastern Europe, has argued that NATO could use Ukrainian territory to deploy missiles capable of reaching Moscow in just five minutes. He warned that Russia could gain a similar capability by deploying warships armed with the latest Zircon hypersonic cruise missile in neutral waters.

Soon after his first election in 2000, Putin ordered the closure of a Soviet-built military surveillance facility in Cuba as he sought to improve ties with Washington. Moscow has intensified contacts with Cuba in recent years as tensions with the U.S. and its allies mounted.

In December 2018, Russia briefly dispatched a pair of its nuclear-capable Tu-160 bombers to Venezuela in a show of support for Venezuelan President Nicolas Maduro amid Western pressure.

Ryabkov said a refusal by the U.S. and its allies to consider the key Russian demand for guarantees against the alliance’s expansion to Ukraine and other ex-Soviet nations makes it hard to discuss the confidence-building steps that Washington says it’s ready to negotiate.

"The U.S. wants to conduct a dialogue on some elements of the security situation ... to ease the tensions and then continue the process of geopolitical and military development of the new territories, coming closer to Moscow," he said. "We have nowhere to retreat."

Ryabkov described U.S. and NATO military deployments and drills near Russia's territory as extremely destabilizing. He said U.S. nuclear-capable strategic bombers flew just 15 kilometers (9 miles) from Russia's border.

"We are constantly facing a provocative military pressure intended to test our strength," he said, adding that he wondered how Americans would react "if our bombers fly within 15 kilometers off some U.S. bases on the East or the West Coast."

The high-stakes diplomacy took place as an estimated 100,000 Russian troops with tanks and other heavy weapons are massed near Ukraine’s eastern border. On Thursday, Sullivan reiterated concerns that Moscow may be laying the groundwork for invading Ukraine by fabricating allegations that Kyiv is preparing to act against Russia. He said the U.S. would be making public some of the reasons for that assessment in the coming days.

Earlier Thursday, Kremlin spokesperson Dmitry Peskov rebuffed the West’s calls for a troop pullback from areas near Ukraine.

"It’s hardly possible for NATO to dictate to us where we should move our armed forces on Russian territory," he said. Peskov asserted this week's talks produced "some positive elements and nuances," but he characterized them as unsuccessful overall.

"The talks were initiated to receive specific answers to concrete principal issues that were raised, and disagreements remained on those principal issues, which is bad," Peskov said in a conference call with reporters.

He warned of a complete rupture in U.S.-Russia relations if proposed sanctions targeting Putin and other top civilian and military leaders are adopted. The measures, proposed by Senate Democrats, would also target leading Russian financial institutions if Moscow sends troops into Ukraine.

OSCE meeting in Vienna

Tensions revolving around Ukraine and Russia's demands on the West again appeared on the table at a Thursday meeting of OSCE in Vienna. Polish Foreign Minister Zbigniew Rau, who assumed the position of the OSCE's chairperson-in-office, noted in his opening speech that "the risk of war in the OSCE area is now greater than ever before in the last 30 years."

Despite this German Foreign Minister Annalena Baerbock said talks between both sides must continue.

"Even though there have been no real movement at the moment, it is important that we are finally returning to the dialogue table," Baerbock said in Brest. Germany's top diplomat added that the European Union had a role to play in the talks if it remained united.

"If we Europeans are united and whole, then we can play our role in the different formats very, very strongly, a role that relies on toughness, but also on dialogue," Baerbock said.

Russia seized the Crimean Peninsula after the ouster of Ukraine’s Moscow-friendly leader and in 2014 also threw its weight behind a separatist insurgency in eastern Ukraine. More than 14,000 people have been killed in nearly eight years of fighting between the Russia-backed rebels and Ukrainian forces.

Asked whether he's worried about possible confrontation, U.N. Secretary-General Antonio Guterres said "it is absolutely essential that the dialogue that is taking place find a way allowing for de-escalation of tension ... to avoid any kind of confrontation that will be a disaster for Europe and for the world."

Meanwhile, the European Union on Thursday extended economic sanctions against Russia for another six months.

"The Council (of the European Union) today decided to prolong the restrictive measures currently targeting specific economic sectors of the Russian Federation by six months, until 31 July 2022," the EU institution representing member states announced in a statement. EU heads of states and governments had already approved the continuation of sanctions during their last summit in December for failing to live up to its commitments to the Minsk Agreement meant to establish peace in eastern Ukraine.

The bloc has been imposing sanctions on Russia's financial, military and energy sectors since 2014, accusing Moscow of destabilizing activities in Ukraine.

Under the restrictions, certain Russian banks and companies have limited access to the bloc's capital markets, while EU operators are prohibited from providing services to Russian financial institutions. The EU also restricts trade in defense-related goods and sensitive technologies that could be used in Russia's energy sector.