Gen Prayuth Chan-ocha has defended the need for the NCPO to stay on after an interim government is formed, and has disclosed plans to send back refugees from Myanmar.

Myanmar commander-in-chief Gen Min Aung Hlaing, centre, walks next to army chief Gen Prayuth Chan-ocha, left, and Supreme Commander Gen Tanasak Patimapragorn during a meeting at the Royal Thai Army headquarters on July 4. (EPA photo)

In his weekly televised address on Friday night, the coup leader said the country still needed a "special tool" to tackle problems under the current circumstances.

A transitional administration to be set up by September will be responsible for administrative affairs while the National Council for Peace and Order (NCPO) will remain responsible for security, the army chief said.

Although he said the army supported checks and balances, the interim government and the NCPO would need to closely consult each other on many issues.

"The normal administration called for by several parties definitely cannot solve all our problems and it will not bear fruit," he said.

An interim government will be formed after royal endorsement of the interim charter, which legal experts have nearly finished drafting.

Underlining its concerns that the situation in the country remains fragile, the NCPO indicated on Thursday that martial law would probably continue to be enforced even after the interim charter takes effect.

Perhaps believing that some civilian administrations installed by previous military regimes have not been successful, Gen Prayuth has never ruled himself out as a candidate for prime minister. He is due to retire from the army at the end of September.

In another development, the army chief announced on Friday night that Thailand had agreed with Myanmar to send back refugees to the neighbouring country.

The agreement was reached in talks with Myanmar commander-in-chief Min Aung Hlaing during his visit to Thailand on July 4.

More than 130,000 refugees fleeing border fighting in Myanmar have been living for years, and some for decades, at nine camps along the border in Thailand.

Gen Prayuth said the two countries agreed that Myanmar would facilitate their safe return to the country on humanitarian grounds.

Thailand calls refugees from Myanmar displaced persons, a status that gives the kingdom full authority to send them back without international interference.

Thailand and Myanmar also pledged cooperation on verifying the nationality of Rohingya migrants staying in Thailand, and on settling the unclear borderline, according to the army chief. They also promised not to support insurgents in their respective countries, he added.

Gen Min Aung Hlaing on July 4 praised the junta for its decision to take control of Thailand to restore security and political stability.

He said Myanmar had experienced a similar situation in 1988, although the circumstances then were worse than they were in Thailand now.

The general was referring to the pro-democracy uprising in Myanmar that culminated in a bloody military reprisal in which thousands of people died.