Russia's foreign minister told a Geneva disarmament meeting on Tuesday that Kyiv has been seeking to acquire nuclear weapons, calling this a real danger that it needed to prevent.

"Ukraine still has Soviet technologies and the means of delivery of such weapons," Sergei Lavrov told the Geneva-based Conference on Disarmament in a pre-recorded address. "We cannot fail to respond to this real danger."

He delivered the speech to a thin crowd since many diplomats including France and Britain staged a walk-out to protest Russia's invasion of Ukraine.

They stood in a circle outside the meeting for the duration of Lavrov's speech, holding a Ukrainian flag. Lavrov was supposed to attend the session in person but the visit was canceled, with Russia accusing unidentified EU states of blocking his flight path.

At the same meeting, Ukraine's foreign minister accused Russia of war crimes through its shelling of his country and called for a special meeting to address Russian aggression and weapons of mass destruction.

Earlier in the session, the president organized a minute of silence for the victims of fighting in Ukraine.