Russian Deputy Foreign Minister Sergey Ryabkov told ABC News during an exclusive interview in Moscow on Monday that he believes the warring parties are close to a deal.

European leaders said they had agreed on Monday any decisions on potential Ukrainian territorial concessions to Russia could only be made once robust security guarantees were in place which should include a European-led multinational force.

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.

While US officials talked up progress in Berlin, there was little detail on how the issue of Ukraine's sovereignty would be resolved.

By Andreas Rinke, Tom Balmforth and Steve Holland BERLIN/WASHINGTON, Dec 15 (Reuters) - U.S. negotiators have offered to provide NATO-style security guarantees for Kyiv as U.S. and European negotiators reported progress in talks on Monday to end the war with Russia,

The head of Britain’s MI6 spy agency says Russian President Vladimir Putin is stalling efforts to end Russia’s war on Ukraine, and is testing the West with tactics that fall “just below the threshold of war.

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.