SEOUL - Former U.S. President Bill Clinton made a surprise visit to North Korea on Tuesday to try to win the release of two jailed American journalists, a move some analysts said could mark the isolated state's return to talks over nuclear weapons.

The White House appeared to play down speculation about a possible breakthrough in U.S.-North Korean relations by characterizing Clinton's trip as private.

While this solely private mission to secure the release of two Americans is on the ground, we will have no comment. We do not want to jeopardize the success of former President Clinton's mission, White House spokesman Robert Gibbs said in a statement.

Clinton's trip followed months of military provocations by the impoverished North, which has turned its back on negotiations with regional powers, including the United States and China, to convince it to give up ambitions to build an atomic arsenal.

North Korea's KCNA news agency said the country's chief nuclear negotiator, Kim Kye-gwan, was among those greeting Clinton -- whose administration was reported to have considered bombing the North's Yongbyon atomic plant in the early 1990s.

Television footage showed a dark-suited, stern-faced Clinton in a vigorous hand shake with one official. He looked less serious when a girl dressed in traditional costume presented him with flowers before he was led to a black limousine.

As soon as he arrives, he will be entering negotiations with the North for the release of the female journalists, South Korea's Yonhap news agency quoted a source as saying.

The two journalists -- Euna Lee and Laura Ling, of U.S. media outlet Current TV co-founded by Clinton's vice president Al Gore -- were arrested on the North Korea-China border in March, accused of illegal entry and being bent on slander.

A North Korean court sentenced them each last month to 12 years hard labor for what it called grave crimes.

Many analysts predicted Pyongyang would use the journalists as leverage to wring concessions from Washington, which led pressure for U.N. sanctions on the North for a May nuclear test.

In Washington, Republican Sen. Lindsey Graham of South Carolina told U.S. television it was not clear whether Clinton had been authorized to discuss policy issues.

It would be nice if it's the foundation for a better relationship, Graham, a prominent member of the Senate Armed Services Committee, told NBC's Today Show.

If he could sit down with the North Koreans and convey a message from the administration and the Congress to be more reasonable when it comes to verifying their nuclear program and getting away from the development of nuclear weapons, it'd be a good thing.

Yun Duk-min of the Institute of Foreign Affairs and National Security in Seoul said the visit held out the possibility of a dramatic turnaround by North Korea that could lead to a new phase of negotiations.

But trade data suggests the North may be resorting more to barter trade to make it more difficult for the international community to pressure Pyongyang through sanctions.

It is the second time a former U.S. president has headed to the communist state to try to defuse a crisis. Former president Jimmy Carter flew there in 1994 when tensions were running high, again over the North's nuclear weapons program.
A senior official traveling with U.S. Secretary of State Hillary Clinton said there would be no comment during the mission. Our interest here is the successful completion of the mission and the safe return of the journalists.

Hillary Clinton, flying to Kenya for a trade conference, enraged Pyongyang's leaders last month by likening them to unruly children seeking attention, adding that they did not deserve it.

SENDING THE WRONG SIGNALS

One analyst said that was exactly what the former president's visit was doing -- rewarding bad behavior.

Clinton's arrival coincides with mounting speculation over succession in Asia's only communist dynasty. Several reports suggest that an increasingly frail-looking Kim Jong-il, 67, has settled on his third son to take over.

It's just what they (North Korea's leaders) need, said B.R. Myers, an expert on the North's state ideology at the South's Dongseo University.

It allows the government to show to a domestic audience, facing deepening poverty, that the nuclear weapons program is making the outside world take it more seriously and the visit will be certain to be portrayed as tribute by the United States.

And it will confirm to North Korea that bad behavior will be rewarded further, Myers said. It sends all the wrong signals.

Bill Clinton had sought better relations, exchanging high-level envoys near the end of his term that fueled expectations that Washington and Pyongyang would end decades of hostility and normalize

ties.

His Secretary of State, Madeleine Albright, visited Pyongyang in 2000 and met supreme leader Kim.

The improvement was short-lived as George W. Bush took office and declared the North part of an axis of evil along with Iran and Iraq.

(Additional reporting by Lucy Hornby in Beijing, Sue Pleming en route to Kenya and David Morgan in Washington; Editing by Ron Popeski and Anthony Boadle)