In an exclusive interview with AFP on Thursday, Rice struck positive but guarded notes on the progress of six-party talks aimed at disabling and eventually dismantling North Korea's nuclear weapons programs.

"I do think the course of disabling has been pretty smooth. It's been cooperative. The North Koreans have taken the steps they said they would take. We've been able to observe them," Rice said.

North Korea staged its first nuclear test in October 2006, but it agreed this year to disable its plutonium-producing plants and declare all nuclear programs and facilities by year-end in return for major energy aid.

And if the North next year dismantles the plants and hands over its plutonium stockpile and any weapons, it can achieve its main objective -- normal ties with the United States and an end to sanctions.

But the process has reportedly hit a key problem -- the North's refusal to address its suspected highly enriched uranium weapons program to the satisfaction of the United States.

The US-supervised disablement is well under way but both South Korean and US officials say the nuclear declaration may not be made until next year.

It is a "remarkable situation" to observe first the shutdown of the reactor at the Yongbyon atomic plant and "then the actual disabling, which now begins to reverse the plutonium program," Rice said.

The top US diplomat said the "jury is still out" on whether North Korea would issue a full and complete declaration on all its nuclear activities by a December 31 deadline.

US President George W. Bush last week answered a verbal message from North Korean leader Kim Jong-Il by urging him to fully disclose his country's nuclear programs.

His remarks followed a "Dear Chairman" letter from Bush, an unprecedented gesture from a man who once labeled the hardline communist state part of an "axis of evil" and who said he loathed Kim.

Rice stressed key steps must still be taken, including "full denuclearization, dismantlement, accounting for the materials and whatever was done with them."

She did not mention a timetable.

"We'd like very much to move forward with that phase because that's where the real beginnings of political engagement and ultimately normalization would be anticipated," Rice said.

"I happen to think that an opening up of North Korea will benefit everybody," she said, adding that "a closed state" like North Korea "is not good for the Korean peninsula, it's not good for Asia."

She said the six-party process has advanced simultaneously the cause of both denuclearization and political openness. In addition to the United States, that diplomatic effort groups China, Japan, Russia, North and South Korea.

"And it's my hope that the North Koreans will go ahead and file an accurate declaration and we can then move forward," Rice said.

Asked if it were "conceivable" for her to make a personal visit to North Korea before Bush's mandate ends in January 2009, she replied: "That would be a little premature to speculate on that but you know nothing is inconceivable."

She added: "But we'd have to be quite a bit further along than we are now."

During a roundtable with the media in Beijing in October 2006, Rice was asked if she could envision going to Pyongyang anytime in her tenure.

"Don't pack your bags," Rice replied.

The last secretary of state to visit North Korea was Madeleine Albright, who served under former president Bill Clinton.