http://news.bbc.co.uk/2/hi/asia-pacific/3206990.stmThe US has hinted at a new solution to the stand-off.
President Bush, on the third leg of a six-nation Asian tour, was upbeat on the subject during talks with Mr Roh.
"We're making good progress on peacefully solving the issue with North Korea," Mr Bush said.
Mr Bush and Mr Roh issued a statement calling on North Korea to resume talks on the issue, and "refrain from any action which would exacerbate the situation".
On Sunday, the US leader ruled out the formal non-aggression treaty with the North that Pyongyang is demanding, but hinted that there may be room for some other form of written security pledge.
Expanding on Mr Bush's comments in a speech to business leaders on Monday, US Secretary of State Colin Powell said he would spend the next few days and weeks fleshing out US proposals to defuse the North Korean nuclear crisis with America's allies.