US President Donald Trump welcomed Thai Prime Minister Prayut Chan-o-cha to the White House on Monday, handing a diplomatic coup to the general who, as army chief in 2014, removed an elected government in a coup d'etat, souring relations with Washington.

"We've had a long and very storied history with Thailand," Mr Trump said before the media was ushered out ahead of the meetings. "We have a very strong relationship right now... and it's getting stronger in the last nine months."

"Our relationship on trade is becoming more and more important and it's a great country to trade with... I think we're going to try to sell a little bit more to you," Mr Trump added, in a reference to the US' trade deficit with Thailand.

In effect, Monday's handshake at the White House followed by a delegation-level working lunch put the relationship with the US' old ally in Asia back on track. Under former president Barack Obama, the US had reduced official contacts after the 2014 coup and cut back its participation in Cobra Gold - the largest multilateral military exercise in Asia. This elicited protests from Thai royalists and triggered a perceptible shift towards China by the Thai regime.

A joint statement on Monday, however, reaffirmed the US-Thai alliance as "a key feature in underpinning peace and stability in the Indo-Pacific".

Mr Trump and Mr Prayut "resolved to further strengthen the alliance through a broad range of measures, including enhanced dialogue, closer coordination, regular exchange of visits, and defence modernisation efforts", it said.

"The two leaders also welcomed closer military-to-military cooperation and joint exercises, including Cobra Gold," it added.

President Trump and Mr Prayut also highlighted the importance of a peaceful and stable South China Sea, and reaffirmed their resolve to implement United Nations Security Council resolutions on North Korea, the statement said. They also welcomed the Myanmar government's commitment to end the violence in Rakhine state.

Still, trade remains an issue. Thailand is among 16 countries being investigated by the Trump administration over high trade deficits.

Mr Trump welcomed progress by the Thai government in cracking down on intellectual property rights violations, as well as "growing investment from Thai companies in the United States and its potential contribution to the creation of jobs for American workers", the joint statement said.