Sergey Ryabkov told ABC News Moscow cannot compromise on key territories.

A 1,000-strong "dark fleet" of rogue tankers evading sanctions has become a new target for the U.S. and Ukraine, according to a senior maritime intelligence analyst.

Donald Trump's envoy will meet the Ukrainian president and European leaders in Berlin to discuss the latest peace plan.

Ukraine has relinquished its ambition of joining the NATO military alliance in exchange for Western security guarantees as a compromise to end the war with Russia, President Volodymyr Zelenskyy said ahead of talks with U.S. envoys in Berlin.

The Kremlin has described Ukraine’s push to join NATO as one of the “root causes” of the conflict. U.S. President Donald Trump has ruled out Ukrainian membership in the Western defensive alliance. Zelensky is searching for compromises that could secure a peace deal to end Russia’s ongoing invasion.

U.S. peace negotiators have told Ukraine during peace talks in Berlin that it must agree to withdraw its forces from the eastern Donetsk region as part of any deal to end the nearly four-year-old war,

U.S. officials have indicated that Putin is open to Ukraine joining the European Union, as well as other security guarantees to Ukraine.