WASHINGTON -- Two weeks after winning re-election to a second term, President Barack Obama will embark on a four-day, three-nation trip to Southeast Asia as he continues to try to leave his imprint on a region increasingly influenced by China.

Obama will meet with leaders in Thailand, attend the East Asia Summit in Cambodia and become the first U.S. president to visit Myanmar, where he will praise the nation’s shift from military rule to fledgling democracy.

The president, who spent part of his childhood in Indonesia, took office four years ago with a pledge to concentrate on Asia, which he said his predecessor neglected. Although the war in Afghanistan and unrest in the Middle East continue to dominate U.S. foreign policy, Obama signaled earlier this year that he will shift some focus to a region with major challenges and opportunities for the United States. Defense Secretary Leon Panetta and Secretary of State Hillary Clinton also will be in the area this week.

Obama’s recent shift is, in part, a response to China’s growing economic and military influence. His trip comes just before China begins its first leadership change in a decade.

“The context for the trip is the pivot to Asia,” said Michael Green, senior vice president for Asia at the Center for Strategic and International Studies. “In some ways, the three countries that he will visit . . . they’re sort of the three troubled children of the pivot. Each has a complicated relationship with the U.S. and with China.”

Obama’s trip comes days after Congress begins debating possible ways to avert spending cuts and tax increases that could throw the economy back into a recession, and after his CIA director abruptly resigned amid a sex scandal that has widened to possibly taint the Marine general who commands U.S.-led forces in Afghanistan.

Obama had planned to travel to Asia whether or not he won last week’s election against Republican Mitt Romney, but some question whether he should be leaving Washington right now.

White House Press Secretary Jay Carney defended the president’s trip, saying Obama will meet with congressional leaders Friday, the day before he flies to Asia, and that he will be engaged in important work overseas expanding U.S. trade and economic ties and supporting democracy.

“The president’s trip to Asia will be an opportunity to build on our successful efforts to refocus on the Asia Pacific as the most rapidly growing and dynamic region in the world,” he told reporters. “The positive economic impact of doing that will be felt for years to come and is elemental to the kind of economic growth that this president foresees for the American economy in the 21st century.”

The White House weighed the investment involved and determined it was well worth Obama’s time, White House National Security Adviser Tom Donilon said, calling the trip part of a “long-term effort to better position” the U.S. in a critical region.

The part of Obama’s trip that will receive the most attention is his historic visit to Myanmar, formerly known as Burma, a nation that was under military rule for five decades until the ruling junta was dissolved in 2011 following an election. Earlier this year, Hillary Clinton became the first secretary of state in five decades to visit Myanmar after a year of political reforms that led the United States to lift sanctions and appoint a full ambassador to the nation.