Dr Rice is due to visit South Korea - where she will attend the inauguration of South Korean President-elect Lee Myung Bak on Monday - as well as China and Japan in the context of six-party negotiations to disarm North Korea.

US officials said Dr Rice has no plans to visit North Korea, even if they added that a landmark, albeit privately-arranged concert that the New York Philharmonic plans to give the same week in Pyongyang could boost diplomacy.

'You know, sometimes the North Koreans don't like our words; maybe they'll like our music. So we'll see,' US nuclear envoy Christopher Hill told reporters in Seoul on Wednesday during his own tour to pave the way for Dr Rice.

Not any closer
Analysts said they saw no public signs that Washington was closer to extracting a full and accurate declaration from the North Koreans on their nuclear activities, including a suspected uranium enrichment program.

Robert Einhorn, a former US government non-proliferation chief who worked on the North Korean nuclear issue, told reporters it appeared that Washington had no indication that North Korea would reveal more about these activities.

Without such an indication, the United States was reluctant to work out a 'sequence' whereby North Korea would receive accelerated deliveries of fuel oil and be removed from a US list of state sponsors of terrorism, he said.

'If the US and if Chris Hill hasn't heard more than that privately, then it is hard to see at this stage how they're going to reach any breakthroughs during the secretary's visit,' Mr Einhorn said.

Great strides have been taken since President George W. Bush rejected a diplomatic solution and branded North Korea as part of the 'axis of evil' with Iran and Iraq.

North Korea, which staged its first nuclear test in October 2006, later agreed to return to six-party negotiations grouping the two Koreas, the United States, China, Russia and Japan.

A landmark deal reached on Feb 13 last year offers the North a million tonnes of fuel oil, normalised ties with the United States and Japan and a formal peace treaty, if it scraps all nuclear programmes and material.

In the current phase the North agreed to disable its atomic plants and fully declare all nuclear programmes by the end of last year.

But it missed the deadline amid a dispute with the US over the declaration.

Pyongyang says it submitted a list in November.

Slow negotiators
Charles Ferguson, a non-proliferation expert at the Council on Foreign Relations, agreed with Mr Einhorn that chances of a breakthrough were slim, partly because the North Koreans were painfully slow negotiators.

On Dr Rice's visit to Tokyo, he added, the Japanese could push for more clarity on the 'sore issue' of a dozen or so Japanese nationals who were adbucted by North Korea decades ago, which are a part of the talks with Pyongyang.

'It's taken a bit of a back burner in Japan, but it can flare up,' Mr Ferguson told reporters.

Dr Rice's trip appears all the more important as Mr Hill acknowledged that 'we're very short of time' after he arrived in South Korea on Tuesday from a trip to China where he met his North Korean counterpart, Mr Kim Kye Gwan.

He wants results before Mr Bush leaves office in January next year.

But Mr Hill, who will join Dr Rice on her tour, added that neither he nor Mr Kim believed the problem over the declaration amounts to a stalemate, with the US diplomat calling it instead a 'rough patch.'

Mr Einhorn said Dr Rice's tour would at the least boost six-party coordination, adding that her meetings with the new government in Seoul could improve the strained ties of the past and ultimately benefit the talks on North Korea.

'I think expectations are very high for an improved relationship between Washington and Seoul,' he added.

Though not connected to the North Korean issue, DrRice will likely face the fallout over the alleged rape of a 14-year-old girl by a US Marine in Okinawa, as the massive US military presence in the country wears thin. -- AFP