PM Prayut Chan-o-cha said Thailand must observe at least 15 days of mourning for King Bhumibol Adulyadej before the royal succession can take place and confirmed there would be no change to the roadmap.
"On the matter of succession, in accordance with the constitution, citizens in Thailand and abroad should not be worried or concerned," Gen Prayut told reporters after a cabinet meeting.
"After at least 15 days of mourning, it will be the appropriate time to enact Section 23 of the constitution," he added, referring to clauses relating to the succession.
The formality involves the cabinet informing the National Legislative Assembly (NLA) about the royal heir and the NLA acknowledging it and inviting him to take the throne.
The prime minister said last week that the coronation of Crown Prince Vajiralongkorn would take place after the cremation of his father, which will follow a year of mourning. However, the prince can become king before his official coronation.
The prime minister also confirmed the roadmap to restore democratic rule, which includes a general election in 2017, will not be affected by the death of King Bhumibol Adulyadej last week.
"Nothing has changed," he told reporters after a cabinet meeting. "The policies of this government, the laws -- including elections -- will be according to the roadmap. Don't ask me when or how it will occur, the roadmap is the roadmap."
Gen Prayut also said the next king would sign the constitution by the timeframe set forth in the roadmap and there should be no delay.
Deputy Prime Minister Wissanu Krea-ngam also confirmed on Tuesday everything had proceeded by the roadmap, which foresees the general election in late 2017.
At the moment, scribes are writing the constitution according to tradition and they should finish early in November. After that, they government has until Nov 9 to submit the charter for royal endorsement. The King will take no more than 90 days to consider it and it is expected to be returned late in December or early in January.
After that, constitution writers will take eight months to write organic laws but Mr Wissanu said they had already prepared some drafts so there was no cause for concern the roadmap would be delayed.
