The agreement, dubbed the “Kuala Lumpur Accord”, commits both countries to an immediate cessation of hostilities, the withdrawal of heavy weapons from conflict zones, and the start of joint de-mining operations.

It also provides for the release of 18 Cambodian prisoners of war and the deployment of Asean observers, including Malaysians, to monitor the truce.

Tensions between Cambodia and Thailand erupted in July into the deadliest clashes in decades, leaving more than 40 people dead and displacing about 300,000.

In his remarks before the signing, US president Donald Trump hailed the accord as a “momentous day for all the people of Southeast Asia”, praising the “courageous leadership” of Cambodian prime minister Hun Manet and Thai prime minister Anutin Charnvirakul.

He also credited Prime Minister Anwar Ibrahim, who is the Asean chair, for hosting the talks, saying Malaysia provided “a neutral place” that helped bring both sides together.

Trump said there had been “a lot of phone calls between the four of us” following the “bloodshed” in July, but said his administration had “got it stopped”.

Anwar, who hosted the ceremony, thanked Trump for his “tenacity and courage” in backing the peace process.

“Thank you, and we admire your commitment. The world needs leaders who are willing to champion peace,” he said.

Both Hun Manet and Anutin expressed their appreciation to Trump for his personal dedication, with the Cambodian premier reiterating that he had nominated the US president for the Nobel Peace Prize in recognition of his role in the negotiations.