US President Joe Biden says he is ready to pursue a new nuclear arms deal with Russia and has called on Moscow to act in good faith as his Russian counterpart Vladimir Putin says there can be no winners in any nuclear war.

Both leaders issued statements as diplomats gathered for a UN conference to review the Treaty on the Non-Proliferation of Nuclear Weapons.

It was supposed to have been held in 2020 but was delayed by the COVID-19 pandemic.

“It occurs at a time of nuclear danger not seen since the height of the Cold War,” UN Secretary-General Antonio Guterres told the conference on Monday.

“Humanity is just one misunderstanding, one miscalculation away from nuclear annihilation.”

He warned that crises “with nuclear undertones are festering”, citing the Middle East, North Korea and Russia’s war in Ukraine.

Within days of Russia’s February 24 invasion, Mr Putin put the country’s deterrence forces – which include nuclear arms – on high alert, citing what he called aggressive statements by NATO leaders and Western economic sanctions against Moscow.

But in a letter to the NPT review conference, Mr Putin wrote: “There can be no winners in a nuclear war and it should never be unleashed, and we stand for equal and indivisible security for all members of the world community.”

Arms control has traditionally been an area in which global progress has been possible despite wider disagreements.

The UN conference takes place five months after Russia invaded Ukraine and as US-China tensions flare over Taiwan.

Moscow and Washington last year extended their New START treaty, which caps the number of strategic nuclear warheads they can deploy and limits the land- and submarine-based missiles and bombers to deliver them, until 2026.

“My administration is ready to expeditiously negotiate a new arms control framework to replace New START when it expires in 2026,” Mr Biden said.

“But negotiation requires a willing partner operating in good faith.

“Russia should demonstrate that it is ready to resume work on nuclear arms control with the United States.”

But Russia’s mission to the UN questioned if the US was ready to negotiate, accusing Washington of withdrawing from talks with Moscow on strategic stability over the Ukraine conflict.

“It is high time Washington made up its mind, stopped rushing around, and told us frankly what it is that they want: escalate the situation in the area of international security or embark on equal negotiations,” Russia’s UN mission said.

Mr Biden also called on China “to engage in talks that will reduce the risk of miscalculation and address destabilising military dynamics”.

US Secretary of State Antony Blinken told the UN conference that Washington was committed to seeking a comprehensive risk reduction package that would include secure communications channels among nuclear weapon states.

He said a return to the 2015 nuclear deal remains the best outcome for the US, Iran and the world, and again accused North Korea of preparing for a seventh nuclear test.

– AAP