Cambodia and Thailand exchanged fire across their disputed border for a fourth day on Sunday, hours after US President Donald Trump announced the two Southeast Asian nations had agreed to ceasefire talks and threatened continued fighting would jeopardize their trade deals with Washington.

Thailand and Cambodia have signaled their readiness to negotiate a ceasefire after mediation by U.S. President Donald Trump.

Thailand has mobilised gunboats to patrol its province bordering Cambodia as conflict between the two nations enters the third day, with death toll climbing to 33 and tens of thousands seeking refuge.

Both countries lay claim to centuries-old worship sites perched on the mountains that divide the two nations, sometimes stoking nationalistic fervor.

The 900-year-old Preah Vihear temple, a Hindu shrine dedicated to Lord Shiva, is perched on a 525 metre cliff in Cambodia's Dangrek mountains.

The renewed fighting comes just hours after US President Donald Trump claimed to have brokered a peace deal through phone diplomacy.Cambodian troops fired on Thai soldiers near Ta Kwai temple in Surin province,

Cambodia is seeking to "internationalise the issue to serve its own political objectives", Thailand’s ambassador to the United Nations Cherdchai Chaivaivid told a closed-door UN Security Council meeting.

Thailand and Cambodia have exchanged fire on their border in a sharp escalation of a conflict that killed at least 12 people, mostly civilians and including two children aged eight and 15.

The conflict over the shared border between the two countries grew on Saturday, in the deadliest conflict between them in more than a decade.

Thailand said late Saturday it agrees in principle to entering a ceasefire with Cambodia and beginning a "bilateral dialogue" aimed at ending the nations' deadliest fighting in more than a decade.

The renewed deadly conflict pits longtime U.S. ally Thailand, with decades of experience ... Some of the projectiles landed near the ancient Preah Vihear temple, a UNESCO World Heritage site in Cambodia’s northern province of the same name, according ...

The current clashes erupted on Thursday with an exchange of fire near Prasat Ta Muen Thom, an ancient temple claimed by both nations. It followed two months of tensions over contested territory that began in late May after a Cambodian soldier was killed in a skirmish.