Speaking to reporters late Wednesday, the prime minister responded to statements made by his deputy prime minister that elections would be postponed to February 2016.
"It is up to the constitutional drafting process," Prayuth said.
"Once the constitution is done, then it would be up to the election commission to stage elections."
The drafting process would be scrutinised in closer detail at the end of 2015, he said. The general denied reports that he wanted to stay in his position indefinitely, saying he was only in power to serve his country.
"If you want me to leave, then tell me to go. That is, if you want this country to fail," Prayuth said.
The United States State Department has said that a delay in a return to an elected government would be "unwise and unjustified." The current government came to power after a bloodless coup in May.
After taking power the government released a roadmap which pointed to elections in late 2015.