He spoke ahead of the first anniversary of Moscow's offensive in Ukraine, and the announcement is expected to be seen by analysts as a major attempt to raise the stakes in Russia's confrontation with the West.

"I have to announce that Russia is suspending its participation in the New START treaty," Putin said in his state of the nation address.

"It is not withdrawing from the treaty, but is suspending its participation," he said to applause from political elites in the audience.

"No one should be under the illusion that global strategic parity can be violated," Putin said.

The announcement came after Moscow said in August that it was suspending US inspections of its military sites under New START. It said it was responding to American obstruction of inspections by Russia, a charge denied by Washington.

Putin has repeatedly issued thinly veiled threats to use nuclear weapons in Ukraine, reviving Cold War-era fears.

On Tuesday, he also accused the US of "developing new types of nuclear weapons".

He warned that if the United States conducts tests of new nuclear weapons, Russia would do the same.

He tasked the defence ministry and the Rosatom state nuclear energy company to ensure the country's "readiness" to conduct nuclear arms tests.

"Of course, we will not be the first to do this," he added.

New START, signed by then president Barack Obama in 2010 when relations were warmer, restricted Russia and the United States to a maximum of 1,550 deployed strategic nuclear warheads each -- a reduction of nearly 30 percent from the previous limit set in 2002.

The agreement was ratified in 2011.

US President Joe Biden shortly after taking office extended New START by five years until 2026, giving time to negotiate while preserving what the Democratic administration sees as an important existing treaty.