The deployment of North Korean troops in Ukraine would be a sign of Russian desperation more than two-and-a-half years into its full-scale invasion of its neighbour, Finland's President Alexander Stubb told Reuters on Tuesday.

For more than a year, Russia has been leaning on its increasingly close ally North Korea for supplies of artillery shells and ballistic missiles to prosecute its grinding war in Ukraine. Now, Ukrainian officials are warning that North Korea plans to expand its assistance by dispatching troops.