U.S. President Donald Trump told Reuters that Ukraine - not Russia - is holding up a potential peace deal, rhetoric that stands in marked contrast to that of European allies, who have consistently argued Moscow has little interest in ending its war in Ukraine.

The death of the last treaty between Russia and the U.S. that limited the size of nuclear arsenals may spark a new arms race, says a former security council director.

Europe should do everything it can to help the US president in his efforts to end the war in Ukraine, Karol Nawrocki said.

A Putin ally claims Trump wants Greenland to deploy missiles, warning it would shatter nuclear stability and mark "the beginning of the end of the world."