President Obama left Seoul this morning to head home, concluding an 8-day, 4-country trip through Asia. Air Force One just landed in Alaska for refueling and he's expected back at the White House tonight.

Reporters traveling bombarded White House aides with questions about the lack of tangible results came from the trip, especially from China.

White House senior adviser David Axelrod said Obama "advanced our goals" over the week by having frank discussions with Asian leaders and presenting a new face to the world.

"This is not an immediate gratification business," Axelrod said. "All of these things require solid diplomacy, relationship building, discussions, and that was the purpose of this trip."

Axelrod also repeated the refrain from the last few days that Obama raised human rights issues more directly than other U.S. leaders have done in the past.

"We didn't come halfway across the world for ticker-tape parades," Axelrod said. "We came here to lay a foundation for progress. We've done that."

As he left, reporters asked Obama to assess the trip.

"It was great. We got a lot of work done," he said.

Obama did an interview with Xiang Xi weekly while in China that was published today.

"It has been a very productive trip," he said. "We have worked on a range of issues of mutual concern to the United States and China, and I think it signifies the continued growth of the relationship that is so important not only to our two peoples but also to the world."

Of the entire trip, the president's reception in Seoul was the most exuberant, with large crowds chanting "Obama" as the presidential motorcade headed to the Osan Air Base, where he spoke to nearly 2,000 troops.

Obama told reporters the welcome ceremony at the presidential mansion there was "the most spectacular ceremony for a state visit that we've been involved with as we've traveled."