Gen Tea Banh said Cambodian law does not allow any movement from other countries to hold political activities in the country.
The whereabouts of red-shirt members and activists facing arrest warrants for failing to report to the National Council for Peace and Order are unknown. Speculations had them crossing the border into Cambodia.
But Gen Tea Banh, who is the deputy prime minister, dismissed the assumption.
The Cambodian general led military leaders to visit Thailand as guests of the Defence Ministry. His entourage included Lt Gen Hun Manet, the deputy Cambodian army chief and a son of Premier Hun Sen.
They met with coup leader Prayuth Chan-ocha at army headquarters to wrap up the two-day trip.
Gen Prayuth said Thailand plans to develop the border with Cambodia to bolster its economy and tourism.
Gen Tea Banh reconfirmed Cambodia's support of the National Council for Peace and Order, saying King Norodom Sihamoni, the prime minister and all Cambodia's top generals supported the moves of the junta to resolve the political situation in Thailand.