Thailand and Cambodia have agreed to an “immediate and unconditional” ceasefire in a significant breakthrough to resolve deadly border clashes that entered a fifth day, Malaysian Prime Minister Anwar Ibrahim said on Monday.

Anwar, who chaired the talks as head of the Association of Southeast Asian Nations regional bloc, said both sides have reached a common understanding to take steps to return to normalcy following what he called frank discussions.

Cambodian Prime Minister Hun Manet and Thai Acting Prime Minister Phumtham Wechayachai have agreed to an “immediate and unconditional ceasefire” with effect from midnight local time on Tuesday, Anwar said as he read out a joint statement.

“This is a vital first step towards de-escalation and the restoration of peace and security,” Anwar said.

Military and officials from both sides will also hold meetings to defuse border tensions, he said. The foreign and defence ministers of Malaysia, Cambodia and Thailand have been instructed to “develop a detailed mechanism” to implement and monitor the ceasefire to ensure sustained peace, he added.

Hun Manet and Phumtam hailed the outcome of the meeting and shook hands at the conclusion of the brief press conference.

Hun Manet said he hoped that bilateral ties could return to normal soon so that some 300,000 villagers evacuated on both sides could return home.

It is “time to start rebuilding trust, confidence and cooperation going forward between Thailand and Cambodia,” he said.

Phuntam said the outcome reflected “Thailand’s desire for a peaceful resolution”.

The fighting flared last Thursday after a land mine explosion along the border wounded five Thai soldiers. Both sides blamed each other for starting the clashes, that have killed at least 35 people and displaced more than 260,000 people on both sides. Both countries recalled their ambassadors and Thailand shut all border crossings with Cambodia, with an exception for migrant Cambodian workers returning home.

The Malaysian meeting followed direct pressure from US President Donald Trump, who has warned that the United States may not proceed with trade deals with either country if hostilities continue. The joint statement said that the US is a co-organiser of the talks, with participation from China. The Chinese and American ambassadors to Malaysia attended the meeting that lasted over two hours.

The violence marks a rare instance of open military confrontation between ASEAN member states, a 10-nation regional bloc that has prided itself on non-aggression, peaceful dialogue and economic cooperation.

Evacuees from both sides of the border earlier prayed for a ceasefire deal.

At an evacuation shelter in Cambodia’s Siem Reap province far away from the border, Ron Mao, 56, said she and her family fled their home a kilometre away from the front line when fighting broke out on Thursday. They took refuge in a shelter but moved again to another camp further away after hearing artillery shelling.

“I don’t want to see this war happen. It’s very difficult and I don’t want to run around like this,” she said. “When I heard our prime minister go to negotiate for peace, I would be very happy if they reached the deal as soon as possible, so that I and my children can return home as soon as possible.”

Thai evacuees echoed the sentiment.

“I beg the government. I want it to end quickly,” said farmer Nakorn Jomkamsing at an evacuation camp in Surin hosting more than 6000 people. “I want to live peacefully. I miss my home, my pets, my pigs, dogs and chicken,” the 63-year-old woman said.

The 800-kilometre frontier between Thailand and Cambodia has been disputed for decades, but past confrontations have been limited and brief. The latest tensions erupted in May when a Cambodian soldier was killed in a confrontation that created a diplomatic rift and roiled Thailand’s domestic politics.