Just minutes before he was scheduled to meet President Xi Jinping of China, the president threatened on social media to resume nuclear testing “on an equal basis” with other countries.

Putin announced successful Poseidon nuclear drone testing as President Donald Trump urged Russia to end the Ukraine war instead of testing missiles on Monday.

"We do not see anything that would give rise to the hypothesis of any substantive work going on there," Rafael Grossi says.

Three days after announcing a test of the nuclear-powered Burevestnik missile, Moscow said on Wednesday it also tested Poseidon, a nuclear-capable underwater drone. The second nuclear weapon test in just a week comes as the talks with the US stalled over Moscow’s reluctance to ceasefire in Ukraine.