"When we compare the current situation with six months ago, I think some of the dangers have subsided" on the Korean Peninsula, Mr Roh said, praising Washington for putting pressure on North Korea on the issue while maintaining a "friendly attitude."
Mr Roh's comments came after he met with British Prime Minister Mr Tony Blair to discuss North Korea's suspected nuclear weapons development.
The crisis flared last October when US officials said North Korea admitted having a secret nuclear program in violation of a 1994 pact with the United States. North Korea has said it has reprocessed its spent nuclear fuel rods, a key step toward the production of nuclear weapons.
US and UN officials are now watching for signs that Pyongyang has begun producing plutonium, a process that emits a kind of krypton gas that US sensors can detect.
The New York Timesreported today that American officials confirmed that sensors on the North Korean border have detected elevated levels of krypton 85.
The Timesalso said American and Asian officials say there is strong evidence North Korea has secretly built a second plant for producing weapons-grade plutonium.
White House Press Secretary Mr Scott McClellan said he would not discuss intelligence matters and, therefore, would not confirm the story.
Mr McClellan noted that North Korea "stated publicly last year that it did have a covert nuclear weapons program."
"They have taken a number of escalating steps in recent months, including expelling IAEA (International Atomic Energy Agency) inspectors and restarting their nuclear facilities," Mr McClellan said yesterday.