Prime Minister Prayut Chan-o-cha will announce next month whether he will take part in politics in the run-up to general elections next year, he said on Tuesday.
May of next year is the most recent deadline that Gen Prayut's junta has set for an election its critics hope will return the country to civilian rule after more than four years of the military government, although it has repeatedly pushed back the timeline.
Since the 2014 military coup, Gen Prayut has shown signs of wanting to stay in power after next year's vote.
"If I will stay on, I will have to look at the law," Gen Prayut told reporters at Government House.
"In September, you will know," he added, but gave no details.
Video of the announcement was captured and posted to her Twitter account by Bangkok Post correspondent Wassana Nanuam. (Video is in Thai.)
The Prime Minister's backers, including some veteran politicians, have made no secret of their support for Gen Prayut and want him to return as prime minister.
Technically, Gen Prayut cannot stand for election under the constitution, because he would have needed to have resigned from his post since 2017 to do so.
However, he could return as Prime Minister if a political party nominated him its frontrunner.
The 2017 military-written constitution offers another route.
He could be chosen as an "outside prime minister" if the House of Representatives and the military-appointed upper house Senate nominate him if the winning party's candidate fails to get enough votes.
The junta has promised to relax its curbs on political activities before the vote to allow political parties to complete administrative tasks between September and December.