Malaysian Prime Minister Anwar Ibrahim says Thailand and Cambodia have agreed to an “immediate and unconditional” ceasefire in an effort to resolve deadly border clashes.

Acting Thai Prime Minister Phumtham Wechayachai and Cambodian Prime Minister Hun Manet met on Monday for ceasefire talks at Anwar’s official residence in Malaysia’s administrative capital, Putrajaya.

“We have seen very positive development and results that would augur well for Cambodia and Thailand,” Anwar said as he was flanked by Phumtham and Hun Manet.

The talks between the two warring Southeast Asian countries hosted by Anwar were aimed at halting fighting over a border dispute that has killed at least 35 people and displaced more than 270,000 from both sides of the Thailand-Cambodia border.

The ambassadors of the United States and China were also present at the meeting.

Anwar said US President Donald Trump and China’s leaders were in close contact with the leaders of the warring countries as well as Malaysia “to find a peaceful resolution to the conflict”.

He said on Monday that both Cambodia and Thailand have agreed to a ceasefire effective at midnight (17:00 GMT). A meeting between the military commanders of both nations will follow on Tuesday, he added.

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

Hun Manet said he had “a very good meeting and very good result that we hope to stop immediately the fighting that have caused many lives lost”.

He also praised Trump’s “decisive” role in paving the way for the talks and the ceasefire, adding that he hopes the agreement will lead to the “rebuilding of trust and confidence” between his country and neighbouring Thailand.

The US president celebrated the agreement in a social media post.

“I am pleased to announce that, after the involvement of President Donald J Trump, both Countries have reached a CEASEFIRE and PEACE,” Trump said. “Congratulations to all! By ending this War, we have saved thousands of lives.”

He added that he had instructed his trade team to restart trade talks with the two nations.

US Secretary of State Marco Rubio also urged all parties to “follow through on their commitments” in a statement on Monday.

In his address, Phumtham, who had expressed doubts about Cambodia’s sincerity before the negotiations in Malaysia, said the ceasefire that would “be carried out successfully in good faith by both sides”.

Al Jazeera’s Rob McBride, reporting from Putrajaya, said the presence of the leaders of Thailand and Cambodia at the talks proved crucial in the positive outcome of the talks.

“Given the high profile visit, there was an expectation” of a breakthrough,” McBride said, while noting Trump’s role in pressing for a quick solution to the conflict.

Al Jazeera’s Tony Cheng, reporting from Thailand’s border province of Surin, said the ceasefire announcement was welcome news for many people, especially those who live along the border and have been displaced by the violence, which broke out into open conflict on Thursday after weeks of tensions and some clashes.

“There are so many people who have been affected by this, and they just want to go home so badly,” he said.

Cheng reported that fighting continued shortly before the talks opened in Malaysia. “We’ve been hearing incoming and outgoing artillery fire even after the talks began,” he said, adding that “a large military build-up” was under way in Thailand.

Thai army spokesperson Colonel Richa Suksuwanon told reporters on Monday that fighting had erupted along the border, and The Associated Press news agency reported gunfire could be heard at dawn in Samrong in Cambodia’s Oddar Meanchey province.

On Sunday, Thailand said one person was killed and another injured by a Cambodian rocket fired at Sisaket province.

Thailand’s military also reported that Cambodian snipers were camping in one of the contested temples on the shared border and accused Phnom Penh of surging soldiers along the border and hammering Thai territory with rockets.

Cambodian Ministry of National Defence spokeswoman Maly Socheata on Monday accused Thailand of deploying “a lot of troops” and firing “heavy weapons” into Cambodian territory.

Maly Socheata said that before dawn on Monday, the Thai military targeted areas near the ancient Ta Muen Thom and Ta Kwai temples, which Cambodia claims are its territory but are disputed by Thailand.

She also accused the Thai military of firing smoke bombs from aircraft over Cambodian territory and heavy weapons at its soldiers, adding that Cambodian troops “were able to successfully repel the attacks”.