South Korean President Roh Moo-hyun met Wednesday with Secretary of State Condoleezza Rice, part of his efforts to smooth differences with the United States over a protracted nuclear standoff with North Korea.

Roh and President Bush, who will meet Thursday, both want the North to return to stalled negotiations aimed at persuading Pyongyang to scrap its self-proclaimed nuclear bomb production program. But bickering has flared occasionally on just how to achieve that.

"The most important thing is that they can get along, and project that to the world," Michael O'Hanlon, a senior fellow of foreign policy studies at the Brookings Institution, said in looking ahead to Roh's meeting with Bush.

"They just totally see the world differently," O'Hanlon said, calling the Roh-Bush relationship perhaps "the single rockiest" of Bush's tenure and "probably the one with the greatest consequences."

There were no immediate details on Roh's private meeting with Rice. Roh was scheduled Wednesday to visit the Korean War Memorial and to meet with U.S. lawmakers and business leaders.

How the two allies handle the North Korean nuclear crisis matters because some believe mixed messages from Washington and Seoul have allowed the reclusive North to boost its nuclear arsenal while falling into deeper isolation.

Efforts to restart the disarmament talks have gained greater urgency in recent weeks as leaders worry about a potential North Korean nuclear weapons test, and after the North decided in July to test launch seven missiles. But so far, no resumption of the negotiations by the Koreas, the United States, Russia, Japan and China is in sight.

Roh's time in Washington will be a low-key affair, in marked contrast to a June trip by the leader of another major U.S. ally in Asia, Japan. Prime Minister Junichiro Koizumi spoke publicly of his "heart-to-heart" friendship with Bush during that visit, and Bush treated Koizumi to a rare presidential tour of the home of the prime minister's musical hero, Elvis Presley, in Memphis, Tennessee.

Roh's trip will not match the glamour of Koizumi's, with only a White House Oval Office meeting and a working lunch with Bush on Thursday, before the South Korean leader travels to the U.S. West Coast.

During their meeting, Roh and Bush will discuss an ambitious U.S.-South Korean free trade proposal and Seoul's desire to retake wartime command of its troops from the United States. The focus, however, will be on North Korea.

Bush favors a hard-line approach, refusing to talk to the North outside of the six-nation talks, which Pyongyang has boycotted since November. Roh has tried to engage Kim Jong Il's communist government.

"North Korean policy has been foundering, in part because North Korea sees the huge gap between Seoul and Washington and drives right through it," O'Hanlon said. "Narrowing that gap at least a little, or preventing it from getting wider, is the beginning of success."

Separately, U.S. lawmakers were expected to consider on Wednesday a North Korean nonproliferation measure and a resolution asking Japan to accept responsibility for the sexual exploitation of women in Korea and other Asian countries during World War II.

Michael Green, Bush's senior adviser on Asia until December, said that Roh and Bush have a good working relationship, but he noted that there will be intense pressure on Roh from some in Seoul to emphasize differences with Washington about North Korea.

In the past, Roh has lobbied Bush to change the tone of U.S. policy on North Korea, an attempt to cater to South Koreans who favor expanding ties with the North, said Green, now an analyst at the Center for Strategic and International Studies.

Roh, who was elected on pledges not to kowtow to the United States, has lashed out at officials in Washington for what he said were attempts to force the collapse of North Korea's regime. He has also faced new lows in his popularity, according to recent surveys.