Surin (Thailand) (AP): Thailand and Cambodia on Sunday signalled their readiness to negotiate an end to a deadly border dispute following mediation efforts by US President Donald Trump. The fighting, now in its fourth day, has killed at least 33 people and displaced more than 168,000.

Trump posted on Truth Social on Saturday that he spoke to the leaders of Thailand and Cambodia and suggested he would not move forward with trade agreements with either country if the hostilities continued. He later said both sides agreed to meet to negotiate a ceasefire.

Cambodian Prime Minister Hun Manet said Sunday his country agreed to pursue an “immediate and unconditional ceasefire.” He said Trump told him that Thailand had also agreed to halt attacks following Trump's conversation with Acting Thai Prime Minister Phumtham Wechayachai.

“This is positive news for the soldiers and people of both countries,” Hun Manet said in a statement.

He said he tasked his deputy, Foreign Minister Prak Sokhonn, to coordinate next steps with US Secretary of State Marco Rubio and to engage directly with Thailand's foreign minister to implement the ceasefire.

Thailand expressed cautious support. Phumtham thanked Trump and said that Thailand agreed in principle to a ceasefire but stressed the need for “sincere intention” from Cambodia, the Thai Foreign Ministry said. Phumtam called for swift bilateral talks to discuss concrete steps toward a peaceful resolution, it said.

The fighting first flared Thursday after a land mine explosion along the border wounded five Thai soldiers. Both sides blamed each other for starting the clashes. Both countries recalled their ambassadors and Thailand closed its border crossings with Cambodia.

Despite the diplomatic efforts, fighting continued Sunday along parts of the contested border, with both sides refusing to budge and trading blame over renewed shelling and troop movements.

Col Richa Suksowanont, a Thai army deputy spokesperson, said Cambodian forces fired heavy artillery into Surin province, including at civilian homes early Sunday. He said Cambodia also launched rocket attacks targeting the ancient Ta Muen Thom temple claimed by both countries, and other areas in a bid to reclaim territory secured by Thai troops. Thai forces responded with long-range artillery to strike Cambodian artillery and rocket launchers.

Richa said Trump's efforts to mediate was a “separate matter.” The battlefield operations will continue and a ceasefire can only happen if Cambodia formally initiates negotiations, he added.

“Any cessation of hostilities cannot be reached while Cambodia is severely lacking in good faith and repeatedly violating the basic principles of human rights and humanitarian law," Thailand's Foreign Ministry said separately.

Cambodian Defense Ministry spokesperson Lt. Gen. Maly Socheata accused Thai forces of escalating the violence with bombardment of Cambodian territory early Sunday, followed by a "large-scale incursion" involving tanks and ground troops in multiple areas.

“Such actions undermine all efforts toward peaceful resolution and expose Thailand's clear intent to escalate rather than de-escalate the conflict,” she said.

Thailand has reported 20 deaths, mostly civilians, while Cambodia said 13 people have been killed. More than 131,000 people in Thailand have evacuated to safe locations and over 37,000 people fled from three Cambodian provinces. Many border villages are mostly deserted, with many schools and hospitals shut.

Pichayut Surasit, an air-conditioning technician in Thailand, said the sudden outbreak of fighting meant leaving his work in Bangkok to return home to protect his family.

“I didn't have the heart to continue with my work when I heard the news. I wanted to come back as soon as possible but I had to wait until the evening,” he said. Now at a shelter in Surin housing some 6,000 evacuees, Pichayut worries for his wife and twin daughters, hoping the conflict will end soon so they can return to their home in Kap Choeng district, one of the hardest hit by shelling.

Bualee Chanduang, a local vendor who moved to the same shelter Thursday with her family and pet rabbit, is counting on swift negotiations to end the violence. “I pray for God to help that both sides can agree to talk and end this war,” she said.

The U.N. Security Council has called on the Association of Southeast Asian Nations, a regional bloc, to mediate peace between the two members. Human Rights Watch has condemned the reported use of cluster munitions, weapons banned by International law, in populated areas, and urged both governments to protect civilians.

The 800-kilometer (500-mile) frontier between Thailand and Cambodia has been disputed for decades, but past confrontations have been limited and brief. The latest tensions flared in May when a Cambodian soldier was killed in a confrontation that created a diplomatic rift and roiled Thailand's domestic politics.