CIVIL society groups on Monday criticised the government for not appealing to the United Nations for help in its ongoing standoff with Thailand over disputed  territory along the border.

Chea Mony, president of the Free Trade Union (FTU), said that if the government had complained to the UN earlier and stuck to their complaint, there would not have been any Cambodians killed over the issue.

At least thee Cambodian soldiers are dead after clashes last week with Thai troops on the border near Preah Vihear temple.

"Despite the fact that both sides sustained injuries of a similar magnitude, we are still filled with regret for the loss of our soldiers," he said.

"If the government had used the UN to solve this problem, there would be no dead soldiers,"  Chea Mony added.

An unknown number of Thai casualties were also inflicted.

Yong Kim Eng, president of the People's Center for Development and Peace, said Monday the government's efforts to resolve the dispute were muddled.

"At one moment, they say they want to complain to the UN. At the next, they don't," he said.

Early on in the three-month standoff, Cambodia threatened to file a formal complaint with the UN Security Council, but quickly backed down.

Council of Ministers spokesman Phay Siphan said Monday that the UN and several "big countries" had encouraged Cambodia to choose negotiations.

"We have already written to the UN and sent information to Asean and Unesco. If these measures don't work, we will find another way," he said.