Thai army said in a statement that it was prepared for a confrontation with Cambodia if the spat escalated.
"The armed forces reaffirmed that all three armed forces -- army, navy and air force -- are ready for confrontation in the area and are confident in our potential to defend Thailand's sovereignty," it said.
"We will neither start fighting or invade into Cambodia first, but we will surely act in self-defence if Cambodia invades into our territory," the army said.
Cambodia's Prime Minister Hun Sen issued an ultimatum on Monday to open wars if Thailand failed to withdraw its troops from an area near Preah Vihear Temple.
Meanwhile Thai Foreign Minister Sompong Amornwiwat said, "All 80 troops will remain in the disputed area because Thailand has overseen that area for 20 to 30 years."
Sompong said of those 80 troops deployed to the area, 20 of them are mine clearance workers and the rest offer protection for the mine clearance troops. Thailand insists it has not encroached in any territory, he said.