Members of a Thai-Cambodian border committee failed to find common ground Monday as they sought resolution to a continued military build-up that has escalated to include tanks and artillery, officials said.
A Cambodian delegation remained in Thailand late Monday, but officials were unsure they would resume negotiations Tuesday.
Monday's meeting was not successful, because the Thai side asked Cambodia to discuss border demarcation that was not acceptable, Defense Minister Tea Banh told VOA Khmer.
Both sides have so far kept calm on both sides of the border, he added.
Foreign Minister Hor Namhong meanwhile sent a request to Singaporean Foreign Minister George Yeo for an Asean inter-ministerial group to solve what he called a "grave situation" where "tension between Thailand and Cambodia is escalating."
"Thai troops with artilleries and tanks are building up along the border, constituting a very serious threat not only to the sovereignty and territorial integrity of Cambodia, but also to peace and stability in our region," Hor Namhong wrote.
More than 4,000 Thai and Cambodian troops have moved to the border near Preah Vihear temple, more than double the number Friday, the Associated Press reported.
Cambodian troops remained in an alert posture Monday, although there was no sign of fighting.
Soldiers on both sides said they remained safe.
One Thai soldier told VOA Khmer he was impatient to leave and was not anxious to fight.
Thai officials maintain their soldiers are firmly on Thai soil, a claim disputed by Cambodia, which claims the land surrounding Preah Vihear temple, an 11th-Century Hindu structure dedicated to the god Shiva.
The temple's July 7 inclusion on a Unesco World Heritage site list was celebrated in Cambodia but led to a political crisis in Thailand. On July 8, a contingent of Thai troops entered a pagoda claimed by Cambodia following the detention by Cambodian police of three Thai protesters in the temple.
Soldiers on both sides of the border at Preah Vihear temple have been ordered not to drink, as the standoff entered its seventh day, government spokesman Khieu Kanharith said.
Most villagers from the Preah Vihear area have fled for fear of fighting, but the situation remained calm Monday. Not all were prepared to go, however.
"I will not leave if there is no order for me to leave," said Van Son, 44, who lives with his wife in a small home at the top of the mountain, about 40 meters from troops north of the temple.