WASHINGTON • President Barack Obama returned to the White House yesterday, ending the last foreign tour of his tenure as he prepares to hand power over to Mr Donald Trump, amid unease about the Republican's volatility and isolationist rhetoric.

Following his final foreign press conference in Peru's capital Lima, Mr Obama headed to the airport, where he spoke with a few people at the foot of Air Force One.

He then jogged up the steps of the presidential plane, turned around to give two brief waves and ducked inside one last time.

His trip was dominated by the deep uncertainty Mr Trump has unleashed about the world order with his attacks on free trade and the United States' role as global policeman.

Amid fears that Mr Trump's administration would scrap free trade deals, Pacific Rim leaders vowed on Sunday to fight protectionism and Chinese officials said more countries are looking to join a China-led trading bloc .

Mr Obama said that an increasingly borderless world has brought "historic gains in prosperity, education and health", but acknowledged that globalisation had both winners and losers.

It was an awkward trip for Mr Obama, who campaigned against Mr Trump as his successor but had to reassure US allies on the future.

He asked the world to treat the billionaire as he himself vowed to do: "Wait and see."

At the same time, he sought to pre-empt his successor on some key issues during the Asia-Pacific Economic Cooperation (Apec) Summit.

He claimed his signature trade agreement in the Asia-Pacific, the Trans-Pacific Partnership (TPP), was still alive despite Mr Trump's vows to kill it, and said he wanted to reach a deal on the Ukraine crisis before leaving office.

In response to Mr Trump's threat to pull out of the 12-nation TPP trade deal, regional leaders said on Sunday that they would push ahead with the deal.

"We reaffirm our commitment to keep our markets open and to fight against all forms of protectionism," they said at the Apec Summit.

China is not part of the TPP and has been pushing an alternative vision of free trade in Asia under the Regional Comprehensive Economic Partnership (RCEP), which does not currently include countries in the Americas.

Mr Obama said he was already hearing calls for a "less ambitious" free trade agreement with fewer protections for workers and environmental standards, a likely reference to the China-led RCEP.

"That kind of agreement would obviously exclude US workers and businesses and access to those markets," he said.

Mr Trump, with his "America First" campaign slogan, sees a United States that for years has been taken for granted by weaker nations and is too quick to intervene in intractable conflicts far away.

But Mr Obama argued for a foreign policy in which the US continues to take on the biggest global problems of the day, lead where others stand on the sidelines and help the least fortunate.

He pointed out that before the order imposed in large measure by the US after World War II, war and famine ravaged the globe.

China is an important country, he told reporters in Lima, but the Chinese did not organise the Paris climate talks, help write the agreement to reduce global warming or undertake the negotiations ensuring that all parties agreed to it.

"Russia is a very significant military power, but they are not worrying right now about how to rebuild after a hurricane in Haiti. We are," said Mr Obama, his voice rising. "And I have said before, that is a burden that we should carry proudly."

Mr Obama said Mr Trump's presidency would probably be far different from his candidacy, and have to accommodate external forces.

"Once you are in the Oval Office, once you begin interacting with world leaders, once you see the complexities of the issues, that has a way of shaping your thinking," Mr Obama said.

AGENCE FRANCE-PRESSE, REUTERS, NYTIMES