WASHINGTON: The White House said on Friday the United States sees no reason to adjust its nuclear posture after Russian President Vladimiar Putin's recent comments warning the West he was not bluffing when he said he'd be ready to use nuclear weapons to defend Russia.

"We obviously take those threats very seriously. But we have not seen any reason to adjust our own nuclear posture at this time," White House Press Secretary Karine Jean-Pierre said.

Zelensky says does not believe Putin will use nuclear arms

Putin on Wednesday ordered Russia's first mobilisation since World War Two and backed a plan to annex swathes of Ukraine, and explicitly raised the spectre of a nuclear conflict.