The US would face a “dire threat” from China, Iran and North Korea if Ukraine is forced into concessions to end its war with Russia, Nato’s secretary-general has warned Donald Trump.

New research shows that the revenues of Russia’s top defence contractors outpaced those of their United States and European counterparts last year, as they increased weapons production more effectively than their Western rivals.

Volodymyr Zelensky has called on the US to convince “sceptics” in Europe that Ukraine should be invited to join Nato. For the first time the Ukrainian president indicated that Kyiv could accept Russian control over some of its territory in order to end the “hot phase of the war”, and on the condition that Ukraine joins Nato.