The helicopter will take off at Preah Vihear Temple in Si Sa Ket province on Sunday.

The PM was speaking during a one-day trip to Cambodia during which he met his counterpart, Hun Sen.

Unsettled borders, both at land and sea, between both countries were high on Thaksin's agenda.

The two countries have been negotiating land border disputes for several years. Demarcation work has been marred by land-mines planted along the border during Cambodia's civil strife.

But they have settled the sea border by agreeing to establish a joint development area.

Describing Cambodia as being more open on talking about land demarcation, Thaksin said any buildings or construction situated less than one kilometre from the border-line should be removed during demarcation.

Thaksin said officials of both sides would try to hammer out an agreement on sharing offshore oil reserves along the border.

"Even if we cannot agree this time, I think we will be closer to an agreement," Thaksin told reporters.

Ministers from the two countries signed a Bt1.3-billion loan deal with Thailand's Exim Bank to finance the upgrading of a highway in northwest Cambodia, running from Siem Reap through Anlong Veng to the Thai border.

Siem Reap is the gateway to the famed Angkor Wat temple complex, Cambodia's biggest tourist attraction. The government is hoping to lure tourists to Anlong Veng, the final holdout of the former Khmer Rouge regime.