Cambodians living in Australia slammed Thailand for allegedly starting a border clash that has left dozens of civilians dead.

Footage shows an emotional protester giving a passionate speech before the crowd around her started chanting 'Cambodia!' in front of the Parliament of Victoria in East Melbourne, on July 27.

The rallyists denounced Thailand's alleged incursion into their territory, carrying Cambodian flags and signs as they called for an end to the conflict.

Cambodian media reported that similar protests were also held in New Zealand, South Korea, the United States, and several European countries.

The escalating military confrontation - the bloodiest in more than a decade - flared in long-disputed border areas as Thailand and Cambodia accused each other of instigating the violence on July 24.

The Thai army claimed the clash began when six armed Cambodian soldiers approached a Thai outpost after a drone was heard near a disputed Khmer temple. Thai troops said they shouted warnings and claimed the Cambodians opened fire first.

However, Cambodia's Defence Ministry accused Thailand of provoking the violence, saying its forces acted in self-defence.

Officials said today at least 35 people have been killed and more than 218,000 displaced on both sides of the border.

US President Donald Trump threatened to pause trade deals with both countries as he urged both sides to end the fighting on Saturday evening.

He said: 'I spoke to both of the prime ministers, and I think by the time I got off, I think they want to settle now.'

Acting Thai Prime Minister Phumtham Wechayachai and Cambodian Prime Minister Hun Manet have reportedly agreed to meet in Malaysia today, July 28, in peace talks facilitated by Malaysian Prime Minister Anwar Ibrahim, chair of the Association of Southeast Asian Nations (ASEAN).