The NATO issue is what the Kremlin describes as a "root cause" of its war in Ukraine.

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

Ukraine claimed it carried out an underwater drone strike on Dec. 15, the first such attack in maritime warfare, that critically damaged a Russian Kilo-class attack submarine at the Russian port of Novorossiysk,

By Trevor Hunnicutt, Steve Holland and Jeff Mason WASHINGTON, Dec 15 (Reuters) - Ukraine could receive security guarantees modeled on NATO’s Article 5 mutual defense pledge under a proposed peace deal with Russia,

U.S. administration officials signaled Monday a peace deal between Russia and Ukraine may be closer than ever.

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.

Russian officials reacted coolly to reports of progress in US-European negotiations to end Moscow's all-out war on Ukraine, as the United States reportedly offered NATO-style security guarantees for Kyiv.

The United States, Ukraine and major European countries have reached consensus on 90 percent of terms for a deal to end Ukraine’s war with Russia, two senior U.S. officials said Monday, but they added questions of territorial control have yet to be resolved.

The sweeping peace framework features “Article Five-like” security guarantees, a multibillion-dollar rebuilding plan, progress on tough territorial disputes, and a possible 50/50 split of the

Former Swedish Foreign Minister Tobias Billström said after the Ukraine war, Europe must be ready for further Russian aggression.

President Volodymyr Zelenskyy says Ukraine’s ability to strike back at Russia gives it leverage in peace talks.