President Trump headed back to Washington after he wrapped up what he claimed was a "tremendously successful" 12-day trip to Asia, but which left some experts questioning whether the tour was more style than substance.

"I think the fruits of our labour are going to be incredible, whether it’s security of our nations, whether it’s security of the world or whether it’s trade,” Mr Trump told reporters aboard Air Force One as the presidential plane departed Manila yesterday on its way to Hawaii.

For the most part, the logistics and pageantry of the trip went off without a hitch. Mr Trump said billions of dollars in new deals had been reached and he spoke about the "many good friends" he made, but he offered no new policy changes or detail on efforts to curtail North Korea's nuclear ambitions. It was meant to be a major focus of the trip.

Mr Trump promised a "major statement" on the trip later this week at the White House.

Richard Javad Heydarian, a Manila-based political expert, said Mr Trump "essentially got nothing out of China. South Koreans are still extremely perturbed by Trump’s unpredictable statements. The TPP (Trans-Pacific Partnership) countries going forward with their own free trade deal was a very clear repudiation of the Trump’s 'fair trade' rhetoric."

Mr Heydarian, author of The Rise of Duterte: A Populist Revolt, said that Mr Trump’s "convivial hobnob" with controversial Philippine President Rodrigo Duterte was by far the most successful leg of the journey.

The President extended his trip by one day to attend an economic summit in the Philippine capital yesterday. However, he left the East Asia Summit early because of delays in the schedule of the meetings. Secretary of State Rex Tillerson attended in his place.

In remarks to reporters before leaving Manila, Mr Trump reiterated several of the points he has stressed throughout his trip to Japan, South Korea, China, Vietnam and the Philippines, such as putting America first on trade issues.

"We've explained that the United States is open for trade, but reciprocal trade. We want fair trade,” he said, adding the US has been taken advantage of by its trading partners.

Mr Trump said $300 billion in deals were inked during the trip. He predicted that this figure would soon triple. Mr Trump campaigned for office on a promise to tear up multilateral trade agreements that he said have harmed the United States.

Mr Trump also underlined his positive rapport with Mr Duterte, a leader who has waged a bloody drug war that has left thousands dead.

"It is very important that we get along with the Philippines and we do," he said, calling the archipelago in the South China Sea a "strategic location."

On Monday, the President touted his “great relationship” with Mr Duterte, who had a strained relationship with Mr Trump’s predecessor, President Obama.

Mr Duterte called Mr Obama a "son of a whore" for criticising the Philippine president's human rights record.

After both sides were accused of failing to adequately discuss human rights issues this week, Mr Duterte and Mr Trump issued a joint statement on Monday saying their meeting "underscored that human rights and the dignity of human life are essential".

The statement also said the two presidents discussed the humanitarian crisis in Myanmar. More than 500,000 Muslim-minority Rohingya have fled the country because of an army-led campaign of violence the United Nations described as "ethnic cleansing".

Reactions to Mr Trump’s visit to the region were mixed.

He largely avoided going off-script with verbal gaffes or antagonistic remarks with one notable exception: In a tweet, Trump bristled at being called "old" by North Korean leader Kim Jong Un. "I would NEVER call him short and fat," Mr Trump countered.

The president also raised an outcry in the U.S. by saying that he believed Russian President Vladimir Putin’s denials of meddling by Moscow in the 2016 election.

Still, Curtis Chin, a former U.S. Ambassador to the Asian Development Bank and Asia Fellow at the Santa Monica-based think tank Milken Institute, saw the trip as a successful engagement that underscored a new U.S. commitment to Asia.

“Amid uncertainty over how a non-diplomat, non-politician president might perform on the diplomatic stage, Trump more than exceeded expectations,” he said. "The president made clear that there can be no separating economic and defence issues. This remains true even as the one-time ‘pivot to Asia’ gives way to a U.S. business pivot to Asia.”

Others, however, felt that the Trump administration’s “America First” trade agenda left a leadership void that regional leaders are filling.

“Historians will date this trip as a key moment in the decline of U.S. power in the Asia-Pacific region, when Asian leaders stepped up and took the reins,” said Annelise Riles, director of Cornell Law School’s Clarke Program in East Asian Law and Culture.

"In both China and Japan, it was Asian leaders, not Trump, who set the agenda. Despite all the red carpet, Trump’s own agenda was largely ignored," she said.

* This article first appeared in our sister title, USA Today