Cambodia called on Thailand on Saturday to pull out its forces from areas Phnom Penh claims as its own, one week since a truce halted deadly clashes along their disputed border.

The decades-old dispute between the Southeast Asian neighbours erupted into military clashes several times last year, with fighting in December killing dozens of people and displacing around one million on both sides.

The two countries agreed a truce on December 27, ending three weeks of clashes.

Cambodia says that during that period, Thailand seized several areas across four border provinces.

In a statement on Saturday, Phnom Penh's foreign ministry demanded the withdrawal of "all Thai military personnel and equipment from the territory of the Kingdom of Cambodia to positions fully consistent with the legally established boundary".

The Thai army has rejected claims it had used force to seize Cambodia territory, insisting its forces were present in areas that had always belonged to Thailand.

The Cambodian foreign ministry also called on Thailand to immediately end "all hostile military activities" along the frontier and "within Cambodian territory".

The two nations' border conflict stems from a dispute over the colonial-era demarcation of their 800-kilometre border, where both sides claim territory and centuries-old temple ruins.

On Friday, Cambodia's Information Minister Neth Pheaktra accused Thailand of launching the "illegal annexation" of the border village of Chouk Chey.

The Thai army disputed Phnom Penh's narrative, and Prime Minister Anutin Charnvirakul said his country "has never breached another country's sovereignty and has acted in line with international regulations".

Anutin was speaking on Friday while visiting troops deployed to the border province of Surin. (AFP)