Thailand’s military leader is to receive royal endorsement at a ceremony in the capital, Bangkok, after taking power in a coup last week.
Army chief Gen Prayuth Chan-ocha, who now leads a junta known as the National Council for Peace and Order (NCPO), is also expected to address the nation.
A new temporary constitution is set to be introduced.
The 86-year-old monarch, King Bhumibol Adulyadej, is not expected to attend the ceremony.
The monarchy is highly respected and royal endorsement is seen as key to legitimising the takeover.
The military seized power in the South East Asian nation last week, saying it planned to return stability to Thailand.
The move followed six months of political deadlock as protesters tried to oust the government of Prime Minister Yingluck Shinawatra. At least 28 people were killed and several hundred injured over the course of the protests.
But the coup – which removed an elected government – has drawn widespread international criticism.
Small anti-coup protests took place in Bangkok over the weekend, despite a military ban on gatherings of more than five people.
Experts have also warned that the coup is unlikely to heal divisions in a nation in which politics have become highly polarised.
An army spokeswoman said that the “ceremony to receive the royal command appointing” Gen Prayuth would take place on Monday morning at army headquarters.
Gen Prayuth will then set out his plans in a televised speech.
The ruling junta is then expected to set up a national legislative assembly that will draw up a temporary constitution with a new prime minister.
Since taking power the military has summoned and detained dozens of key political figures, including Ms Yingluck. Journalists and academics are also among those who have been called in.
Tight controls have also been placed on the media.