US Secretary of State Mike Pompeo has pledged North Korea can look forward to "a future brimming with peace and prosperity" if it agrees to quickly give up its nuclear weapons.
"If North Korea takes bold action to quickly denuclearise, the United States is prepared to work with North Korea to achieve prosperity on the par with our South Korean friends," Pompeo told a news conference after talks with his South Korean counterpart in Washington.
"If Chairman Kim chooses the right path, there is a future brimming with peace and prosperity for the North Korean people," he said.
Pompeo, who returned from Pyongyang this week with three Americans who had been held prisoner by North Korea, said the release of men had helped set conditions for a successful meeting between Trump and Kim in Singapore on June 12.
However, his comments made clear that the two sides remained far apart on the key issue of what they mean by denuclearisation.
Pompeo said he had "good, substantive" conversations with Kim in Pyongyang in what was his second meeting with the North Korea leader in less that six weeks, and believed both sides understood the ultimate goal of the summit.
North Korea's development of nuclear weapons and missiles capable of reaching the United States brought exchanges of bellicose rhetoric between Trump and Kim last year that raised fears of a new war on the Korean peninsula.
In spite of an easing of tensions and a return to dialogue in recent months, North Korea has given no indication that it is willing to go beyond statements of broad support for the concept of denuclearisation.
Pompeo said US aim was clear - "to ensure that North Korean doesn't possess the capacity to threaten, not only the United States but the world, with nuclear weapons."
South Korean Foreign Minister Kang Kyung-wha stressed that sanctions against Pyongyang would not be lifted until it had taken concrete steps to denuclearise.
