Prime Minister Prayut Chan-o-cha said he would hope to carry on in office as premier for a maximum of two years after the next general election, and then find a suitable successor when his tenure expires.
As reporters at Government House repeatedly quizzed him about his political future, Gen Prayut said yesterday: "If I am able to stay on as prime minister, I will do so only until 2025."
"I will do my best and then find a suitable and acceptable successor."
These were the first remarks he has made about his political future in several months, with the House's four-year term due to expire in March.
On whether he will join the newly established United Thai Nation Party (UTN), also known as Ruam Thai Sang Chart, Gen Prayut said: "I will speak about it later."
If he is re-elected after the polls expected in the first half of next year, he will be eligible to remain in office until 2025, according to a ruling by the Constitutional Court in September concerning the eight-year limit on a prime minister's tenure.
Some pundits expect him to join the UTN led by Pirapan Salirathavibhaga, a former Democrat Party MP who serves as an adviser to the prime minister.
Mr Pirapan said earlier that the UTN would welcome Gen Prayut if he decided to leave the ruling Palang Pracharath Party (PPRP).
The UTN was founded in March last year by Seksakol Atthawong, a former aide to the prime minister. It was formed to back Gen Prayut's potential return as premier.
The chances of him moving to the UTN increased after he reportedly met Deputy Prime Minister and PPRP leader Prawit Wongsuwon at the office of the Foundation for the Conservation of Forests in Five Adjoining Provinces in the compound of the 1st Infantry Regiment in Bangkok on Nov 20.
Gen Prayut is believed to have informed Gen Prawit of his plan to switch parties.
Akanat Promphan, secretary-general of the UTN, yesterday denied reports about a possible merger with the Action Coalition for Thailand (ACT) Party, which was co-founded by former protest leader Suthep Thaugsuan, who is Mr Akanat's stepfather.
Members of the UTN fear such a merger would cause its popularity to drop.
"Mr Suthep never interferes with my work," he said of his stepfather. "In our family, I respect him as a father. In politics, we may have different opinions but that is normal."
Asked if some MPs plan to defect from the ACT as rumoured, Mr Akanat said MPs often switch parties before elections to bolster their chances.