The joint appeal came from Japan's atomic bomb survivors' group Nihon Hidankyo, which won last year's Nobel; 2017 laureate the International Campaign to Abolish Nuclear Weapons (ICAN); and the 1985 winner, International Physicians for the Prevention of Nuclear War.

They sent a joint letter to the two leaders, ICAN said in a statement Monday.

"At this moment of extreme nuclear danger, we call on you to take urgent steps to de-escalate tensions and to engage in meaningful negotiations for nuclear disarmament," they wrote to US President Donald Trump and his Russian counterpart Vladimir Putin.

The two countries between them control 90 percent of the world's nuclear weapons.

The groups said they were prompted to write their letter following Trump's suggestion after returning to power in January that he wanted the world to "denuclearise", and the Kremlin's expressed openness to the idea.

"The current climate surrounding nuclear weapons is the most volatile in decades," they said, warning of potential "catastrophic consequences for all humankind".

The Nobel laureates called in their letter on the two leaders to follow the example set by their predecessors Ronald Reagan and Mikhail Gorbachev.

The then US and Soviet leaders met in Iceland in 1986 during the Cold War and agreed the deepest cuts ever in their countries' nuclear forces.

"The expansion of nuclear weapons capabilities is not a route to safety," the groups argued. "It only increases the risk these weapons will be used by accident or design.

"The only viable security strategy is one that moves the world away from the brink of nuclear catastrophe and prioritises disarmament," they added.

"Nuclear weapons are not an inevitable force of nature that must be endured," they said.

"They were built by human hands, and they can be dismantled by human hands. All that's required is political will."