President Vladimir Putin says Russia will suspend its role in the last remaining nuclear arms treaty with the US — designed to prevent nuclear war — as he accused the West of wanting to wipe out his country.

Mr Putin gave a blustering landmark speech nearly a year after invading Ukraine and vowed to continue the grinding war.

US President Joe Biden also spoke while in Poland — and after a surprise visit to Ukraine — and foreshadowed more global sanctions against Moscow as he said Russia would never claim victory.

Mr Putin said Russia “was forced” to suspend its role in the New START nuclear treaty with the United States because of the threat to his country’s existence.

He warned that Russia could resume nuclear tests.

The New START treaty was agreed to in 2010 and is aimed at preventing a nuclear war.

The pact is the last major arms control treaty between the Cold War rivals.

It limits the number of nuclear warheads the world’s two biggest nuclear powers can deploy and was due to expire in 2026.

World ‘more dangerous’

NATO Secretary-General Jens Stoltenberg said Russia’s decision made the world a more dangerous place and urged Moscow to reconsider.

“More nuclear weapons and less arms control makes the world more dangerous,” Mr Stoltenberg told reporters.

“It is President Putin who started this imperial war of conquest … As Putin made clear today, he’s preparing for more war … Putin must not win … It would be dangerous for our own security and the whole world,” he added according to Reuters.

Mr Putin said Russia would achieve its war aims and accused the United States and Europe of trying to destroy his nation.

“The elites of the West do not hide their purpose. But they also cannot fail to realise that it is impossible to defeat Russia on the battlefield,” a defiant Mr Putin told his country’s political and military elite.

The Russian leader insisted some people in the US were thinking about resuming nuclear testing.

Russia’s defence ministry and nuclear corporation should therefore be ready to test Russian nuclear weapons if necessary, he said.

“Of course, we will not do this first. But if the United States conducts tests, then we will. No one should have dangerous illusions that global strategic parity can be destroyed,” Mr Putin said.

In Athens, US Secretary of State Antony Blinken said Russia’s decision to back out of the treaty was “unfortunate and irresponsible”.

“We’ll be watching carefully to see what Russia actually does. We’ll of course make sure that in any event, we are postured appropriately for the security of our own country and that of our allies.”

Russia and the United States have vast arsenals of nuclear weapons left over from the Cold War.

Between them, they hold 90 per cent of the world’s nuclear warheads.

The New START Treaty limited both sides to 1550 warheads on deployed intercontinental ballistic missiles, submarine ballistic missiles and heavy bombers.

In essence, Mr Putin is warning that he can dismantle the architecture of nuclear arms control — including the big powers’ moratorium on nuclear testing — in an attempt to get the US and its allies to back off in Ukraine.

After the US dropped nuclear bombs on the Japanese cities of Hiroshima and Nagasaki in 1945, other powers sought to develop their own nuclear weapons and more than 2000 tests were conducted during the Cold War.

But since the Soviet Union collapsed in 1991, only a few countries have tested nuclear weapons, according to the Arms Control Association: the US last in 1992, China last in 1996, India in 1998 and North Korea last in 2017.

The Soviet Union last tested in 1990, according to the Arms Control Association.

Mr Putin said he had information that the US was developing new types of nuclear weapons.

“In this situation, the Russian defence ministry and (state nuclear energy company) Rosatom must ensure readiness for the testing of Russian nuclear weapons,” Mr Putin said.

The US said in its 2022 Nuclear Posture Review that Russia and China were expanding and modernising their nuclear forces, and that the US would pursue an approach based on arms control to head off costly arms races.

Speaking for one hour and 45 minutes flanked by a total of eight tricolour Russian flags, Mr Putin vowed to continue with Russia’s year-long war in Ukraine.

He also sought to justify the war, saying it had been forced on Russia and that he understood the pain of the families of those who had fallen in battle.

Ukraine and its allies reject that narrative and say the expansion of the NATO military eastwards since the end of the Cold War is no justification for what they say is an imperial-style land grab doomed to failure.