A Ukrainian drone strike sparked fires at a Black Sea port in Russia Sunday, officials said, as Moscow claimed further battlefield gains and ahead of new talks aimed at ending the nearly four-year war with Ukraine.

Two people were wounded in the attack on the port of Taman in the Krasnodar region, which damaged an oil storage tank, warehouse and terminals, according to regional Gov. Veniamin Kondratyev.

Meanwhile, falling debris from Russian drones damaged civilian and transport infrastructure in Ukraine's Odesa region, officials said, disrupting the power and water supply.

Ukraine's long-range drone strikes on Russian energy sites aim to deprive Moscow of the oil export revenue it needs to pursue its full-scale invasion.

Russia wants to cripple the Ukrainian power grid, seeking to deny civilians access to heat, light and running water in what Kyiv officials say is an attempt to "weaponize winter."

The attacks came ahead of another round of U.S.-brokered talks between envoys from Russia and Ukraine Tuesday and Wednesday in Geneva, just before the fourth anniversary of the all-out Russian invasion of its neighbor on Feb. 22.

Speaking at the Munich Security Conference in Germany on Saturday, Ukrainian President Volodymyr Zelenskyy suggested there were still questions remaining over future security guarantees for his country.

Zelenskyy also questioned how the concept of a free trade zone – proposed by the U.S. – would work in the Donbas region, which Russia insists Kyiv must give up for peace.

He said the Americans want peace as quickly as possible and that the U.S. team wants to sign all the agreements on Ukraine at the same time, whereas Ukraine wants guarantees for the country's future security signed first.

Zelenskyy's concerns were echoed by Sen. Jeanne Shaheen, a ranking member of the U.S. Senate Foreign Relations Committee.

"Unless we have real security guarantees on whatever peace agreement is ultimately determined, we are going to be here again, because one of the things we know is that Russia has geared up not just for Ukraine, but to go beyond Ukraine," she told reporters in Munich Sunday.

European Union foreign policy chief Kaja Kallas said Russia was hoping to win diplomatically what it had failed to achieve on the battlefield, and was banking on the U.S. to deliver concessions at the negotiating table.

Kallas, however, told the Munich conference Sunday that key Russian demands – including the lifting of sanctions and unfreezing of assets – were decisions for Europe.

"If we want a sustainable peace, then we need concessions also from the Russian side," she said.

Previous U.S.-led efforts to find consensus on ending the war, most recently two rounds of talks in Abu Dhabi, the capital of the United Arab Emirates, have failed to resolve difficult issues, such as the future of Ukraine's Donbas industrial heartland that is largely occupied by Russian forces.

Moscow claims further gains

Also Sunday, the Russian Defence Ministry said that army chief Valery Gerasimov visited Moscow's troops in Ukraine and said the Kremlin's forces seized a dozen eastern villages in February.

"In two weeks of February, despite severe winter conditions, combined forces and military units of the joint task force liberated 12 settlements," Gerasimov said.

The pace of Moscow's advance picked up in Autumn, but Russia has not reached its goal to seize the Donetsk region in four years of war.

Russia demands that Kyiv withdraw from the Donetsk region for any deal to end the conflict – terms unacceptable to Ukraine.

Gerasimov said Moscow's troops were moving in the direction of Sloviansk – an industrial hub that briefly fell to pro-Russian separatists in 2014 and which has been under frequent Russian attack.

Moscow's forces are around 15 kilometers (9 miles) from the city.

Moscow claims the Donetsk, Lugansk, Zaporizhzhia and Kherson regions as its own.

But it has also advanced into other Ukrainian regions.

Gerasimov said Russia was "expanding a security zone" in border areas in the northeastern Sumy and Kharkiv region, where it controls pockets of territory.

The army chief also said he would discuss with officers "further actions in the Dnipropetrovsk direction."

Russian forces crossed into the Dnipropetrovsk region last summer in their push westwards – but the Kremlin has never laid an official claim on the region.

Russian leader Vladimir Putin has repeatedly said Moscow is intent on seizing the whole of the Donetsk region by force if diplomacy fails.