A US envoy plans to spend the coming week in Asia determining if the time is right to talk with North Korea, as tensions ease a notch but a party meeting in the secretive state raises new questions.

Stephen Bosworth, the US pointman on North Korea, will head Sunday to Seoul followed by stops in Tokyo and Beijing. His counterparts from China, Japan and South Korea each recently visited Washington for talks.

The rush of diplomacy comes amid a slight easing of friction surrounding North Korea, with the United States allowing charities to fly in relief in the wake of floods and South Korea considering aid of its own.

US officials and analysts expect the United States will eventually sit down for formal talks with North Korea. But few foresee breakthroughs amid signs the nuclear-armed regime is in the throes of leadership succession.

North Korea and China, its main ally, have been pushing for a resumption of six-way denuclearization talks from which Pyongyang stormed out last year.

But President Barack Obama's administration has insisted on what it calls "strategic patience," saying it will not rush into talks and instead wants North Korea to make clear it abides by a 2005 deal to give up nuclear weapons.

"We will be responsive if North Korea begins to move in what we consider to be a constructive direction," said Philip Crowley, the State Department spokesman.

"In terms of resumption of the six-party process, of course we are open to that possibility, but North Korea will have to take some actions and change the status quo before we would consider that fruitful," Crowley said.

Kurt Campbell, the US assistant secretary of state for East Asia, said that North Korea needed to ease tensions further with South Korea for any denuclearization talks to move ahead.

"We believe that it will be critical for there to be some element of reconciliation between the North and South for any process to move forward," Campbell said Thursday.

South Korea and the United States concluded in late May that North Korea torpedoed South Korea's Choenan ship, killing 46 people in one of the divided peninsula's deadliest incidents in decades.

Washington and Seoul have called on the North to admit responsibility and apologize.

But Scott Snyder, director of the Center for US-Korea Policy at The Asia Foundation, said that the recent humanitarian aid showed that the Cheonan sinking was no longer seen as the sole issue in relations with North Korea.

"Things are cooling off," Snyder said. "I think that there is greater room for maneuverability in terms of trying to improve the situation."

But uncertainty about North Korea's leadership is casting a pall over US calculations.

"The question of political stability and leadership succession in North Korea is the issue that makes formulating a policy toward the North Korea the most difficult at this stage," Snyder said.

"It's hard to predict whether any North Korean commitment would be sustainable," he said.

North Korea is believed either to have begun or to be on the verge of opening its most important political gathering in 30 years to anoint a successor to ailing 68-year-old strongman Kim Jong-Il.

A number of observers believe that Kim has selected his youngest son Kim Jong-Un -- who is in his 20s and has little political experience -- as the third leader in the communist dynasty.

US officials are offering no predictions on what will happen at the meeting.

"Quite honestly, we don't know," Crowley said.