Barack Obama left Washington for his final G20 summit as US president and his 11th trip to Asia following his famous foreign policy "pivot" to the region.
Obama is attending his last meeting of leaders of the Group of 20 economic powers September 4-5 in Hangzhou, eastern China.
Before heading off to Asia, Obama has a planned stop in Hawaii to address a major gathering of international conservationists.
The president's plane, Air Force One, took off from Andrews Air Force base just outside Washington shortly before 11 am (1500 GMT) Wednesday.
Ben Rhodes, a top White House advisor on foreign and security matters, said Obama's agenda is packed with priorities for the waning days of his presidency, which ends in a little more than four months.
On his schedule are "a wide-range of global, regional and bilateral issues," with world leaders, including in-depth meetings with Chinese President Xi Jinping, the White House said.
"Three big pieces of the presidency are going to be front and center here, through climate change, the global economy and the Asia Pacific region. And I think the schedule will illustrate that," Rhodes said.
US Treasury Secretary Jacob Lew, who is accompanying the president on the trip, said Wednesday that Obama would call for broader fiscal stimulus from other economies and press Beijing to limit steel capacity.
He will also ask China for steel industry reforms, highlighting an issue that has threatened steel producers around the world, the US treasury chief said.
Obama also has plans to meet his Turkish counterpart Recep Tayyip Erdogan on the sidelines of the G20 summit, with the war against the Islamic State group high on the list of talking points.
After departing China, Obama will take part in the ASEAN summit in Laos September 6-8, attended by major regional powers such as China, Japan, South Korea, Australia and Russia.
He will be the first US president ever to travel to Laos, which this year holds the presidency of the Association of Southeast Asian Nations.
On the sidelines of that gathering, Obama has plans to meet with the new firebrand Philippine leader, Rodrigo Duterte, despite concerns over a brutal crackdown on crime that has claimed more than 2,000 lives.
Despite the expected arrival Wednesday of Hurricane Madeline, which is barreling down on the Big Island of Hawaii, Obama is scheduled to deliver Thursday's opening address of the World Conservation Congress.
The Hawaii-born commander-in-chief, who spent years of his childhood in Indonesia, early in his presidency declared himself "America's first Pacific president," and has sought to bolster trade and diplomatic ties with the populous, fast-growing region.