US President Barack Obama says he will discuss further nuclear arms cuts with newly-elected Russian President Vladimir Putin in May.
President Obama made the comments during an address at a summit aimed at reducing the risk of nuclear terrorism.
The meeting in Seoul involves representatives from some 50 countries.
Speaking at Hankuk University, Mr Obama reiterated his commitment towards ”a world without nuclear weapons” and also addressed China and North Korea.
He is looking forward to meeting Mr Putin, he said.
Mr Obama would seek to follow on from the New Start treaty he struck in 2010 with outgoing Russian leader Dmitry Medvedev in 2010.
The New Start (Strategic Arms Reduction Treaty) deal agreed between Washington and Moscow aims to replace its lapsed predecessor, Start.
It trims US and Russian nuclear arsenals to 1,550 deployed nuclear warheads – a cut of about 30% from a limit set previously.
The treaty would also allow each side visually to inspect the other’s nuclear capability, with the aim of verifying how many warheads each missile carries.
In addition, there will be legally binding limits on the number of warheads and missiles that can be deployed on land, on submarines, and on bombers, at any one time.