Russia lamented that its views were not addressed in United States' response to its security proposals to end tensions over Ukraine Thursday, but added that Moscow would not respond hastily.

"It cannot be said that our views were taken into account, or that a readiness to take our concerns into account was demonstrated," Kremlin spokesperson Dmitry Peskov told reporters, adding the documents, delivered by Washington in coordination with its NATO allies Wednesday, were in the hands of President Vladimir Putin.

"All these papers are with the president," he said. "Let's not rush into assessments, it takes time to analyze," he added.

Peskov said Washington and NATO had requested the documents remain confidential, but given how many details had already been revealed by Western officials "it really might not be worth it."

The U.S. rejection of Russia's main demands to resolve the crisis over Ukraine leaves little ground for optimism, the Kremlin spokesperson said Thursday, while adding that dialogue was still possible.

Tensions have soared in recent weeks, as the U.S. and its NATO allies expressed fear that a buildup of about 100,000 Russian troops near Ukraine signaled that Moscow is planning to invade its ex-Soviet neighbor. Russia denies having any such plans – and has laid out a series of demands it says will improve security in Europe.

But as expected, the U.S. and the Western alliance firmly rejected any concessions on Moscow's main points Wednesday, refusing to permanently ban Ukraine from joining NATO and saying allied deployments of troops and military equipment in Eastern Europe are nonnegotiable. The U.S., however, did outline areas in which some of Russia's concerns might be addressed, possibly offering a path to de-escalation.

"There is no change, there will be no change," U.S. Secretary of State Antony Blinken said, repeating the warning that any Russian incursion into Ukraine would be met with massive consequences and severe economic costs.

Russian Foreign Minister Sergey Lavrov said Thursday that the U.S.' response to Moscow's security demands over Ukraine did not address its main concern, but it would be possible to move forward.

"There was no positive response to the main question" regarding Moscow's request for banning Ukraine from joining NATO, Lavrov said in a statement, but "there is a response which gives hope for the start of a serious conversation on secondary questions."

All eyes are now on Russia and its response amid fears that Europe could again be plunged into war. That decision rests squarely with Putin.

The evasive official comments suggest that it's Putin who single-handedly determines Russia's next moves. The Russian leader has warned that he would order unspecified "military-technical measures" if the West refuses to heed the Russian security demands.

Peskov added that Putin and U.S. President Joe Biden will decide whether they need to have another conversation following two calls last month.

While the diplomacy sputters on, so do maneuvers on both sides that have escalated tensions. Russia has launched a series of military drills: Motorized infantry and artillery units in southwestern Russia practiced firing live ammunition, warplanes in Kaliningrad on the Baltic Sea performed bombing runs, dozens of warships sailed for training exercises in the Black Sea and the Arctic, and Russian fighter jets and paratroopers arrived in Belarus for joint war games.

Meanwhile, NATO said it was bolstering its deterrence in the Baltic Sea region, and the U.S. ordered 8,500 troops on higher alert for potential deployment to Europe.

Amid the fears of the Russian invasion in Ukraine, a top Putin associate alleged that Ukraine has become a Western tool to contain Russia.

"Ukraine has become a toy at the hands of NATO and, primarily, the United States, which are using it as an instrument of geopolitical pressure against Russia," Dmitry Medvedev, a deputy head of Russia's Security Council, said in an interview with Russian media.

He acknowledged that a Russia-NATO conflict "would be the most dramatic and simply catastrophic scenario, and I hope it will never happen."

Medvedev argued that Moscow sees no point in talking to Ukrainian President Volodymyr Zelenskyy, but voiced hope that the Ukrainians would eventually become "weary of that bedlam and elect the leadership that would pursue policies ... aimed at normal economic relations with Russia."

Medvedev's comment follows a British claim that the Kremlin is seeking to replace Ukraine's government with a pro-Moscow administration – an allegation Russia denied.

In 2014, following the ouster of a Kremlin-friendly president in Kyiv, Moscow annexed Ukraine's Crimean Peninsula and threw its weight behind a separatist insurgency in the country's eastern industrial heartland. Fighting between Ukrainian forces and Russia-backed rebels has killed over 14,000 people, and efforts to reach a settlement have stalled.

While a senior Russian diplomat has pointedly refused to rule out military deployments to Cuba and Venezuela, Medvedev expressed skepticism about such a prospect.

"Cuba and Venezuela are aiming to come out of isolation and restore normal relations with the U.S. to a certain extent, so there can't be any talk about setting up a base there as it happened during the Soviet times," he said.

More talks in two weeks

The Kremlin Deputy Chief of Staff Dmitry Kozak said the talks were "not simple" but that another round would take place in two weeks in Berlin.

After the so-called Normandy Format talks, France said that the envoys committed to a fragile July 2020 cease-fire in eastern Ukraine between government forces and pro-Moscow separatists.

"We need a supplementary pause. We hope that this process will have results in two weeks," Kozak said.

Ukrainian Foreign Minister Dmytro Kuleba on Thursday hailed the talks as a positive sign.

"The good news is that advisers agreed to meet in Berlin in two weeks, which means that at least for the next two weeks, Russia is likely to remain on a diplomatic track," Kuleba told reporters in Copenhagen.

Biden, who spoke with European leaders via videoconference on Tuesday, said any Russian military attack on Ukraine would trigger "enormous consequences" and could even "change the world."

The U.S. on Wednesday again encouraged its citizens to leave Ukraine, warning an invasion could be imminent. But Ukraine's government, hoping to prevent panic, has played down the dangers and sought to offer ways out.

Kuleba told reporters on Wednesday that the Russian troops posed "a threat to Ukraine" but that the numbers deployed were "insufficient for a full-scale offensive."