US does not have any sign Russia is preparing to use a nuclear weapon, State Dept says

The United States does not have any sign that Russia is preparing to use a nuclear weapon and will continue to monitor carefully, State Department spokesperson Matthew Miller told reporters on Thursday after Russian President Vladimir Putin warned that Moscow had weapons to strike targets in the West.

"It is not the first time we have seen irresponsible rhetoric from Vladimir Putin. It is no way for the leader of a nuclear armed state to speak," Miller said.

Putin earlier on Thursday told Western countries they risked provoking a nuclear war if they sent troops to fight in Ukraine.