South Korea has said it was seeking high-level talks this month with North Korea to prepare for a summit and that South Korean President Moon Jae-in may meet Donald Trump before the US president's planned meeting with the North Korean leader.
Amid a flurry of diplomacy from Asia to Europe to Washington, Mr Trump reaffirmed his plan to meet with North Korea's Kim Jong Un by the end of May during a phone call earlier with Mr Moon and both voiced "cautious optimism" about efforts to resolve the crisis over North Korea's nuclear weapons.
A White House statement said President Trump and Mr Moon discussed preparations for their upcoming engagements with Pyongyang and agreed that "concrete actions," not words, were the key to denuclearisation of the Korean peninsula.
They "emphasised that a brighter future is available for North Korea, if it chooses the correct path," it said.
Earlier, Moon Jae-in's chief of staff, Im Jong-seok, said proposed North-South talks in late March would cover key agenda topics and other details of the pending summit.
If North Korea agrees to the talks, they would offer an opportunity for Pyongyang to break its silence on what Seoul says is Kim Jong Un's desire to meet President Trump and President Moon Jae-inand his willingness to freeze his country's nuclear and missile programmes.