Kyiv has now expressed readiness to drop its bid to join the NATO military alliance if the U.S. and other Western nations give it similar security guarantees.

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.

Two U.S. officials who spoke on the condition of anonymity said the arrangement would be similar to the NATO mutual defense agreement. But crucial details remain unsettled as negotiators seek a deal that Russia will approve.

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,

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.

Two days of intense negotiations between Ukraine, the U.S. and European officials resulted in clear progress on security guarantees for Ukraine but left significant gaps on the issue of territory, U.S. officials told reporters on Monday.

Ukraine could receive security guarantees modeled on NATO’s Article 5 mutual defense pledge under a proposed peace deal with Russia, U.S. officials said on Monday — an unprecedented offer aimed at ending the war sparked by Moscow’s 2022 invasion.

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