Gen Prawit Wongsuwon has attended his first meeting as chief strategist of Palang Pracharath Party.
The deputy prime minister showed up at the party's headquarters on Ratchada Road in Bangkok on Tuesday.
He thanked party members and said he hoped to see cooperation and unity among the members.
"From now on, I'm a full-time politician," he said.
He added PPRP was not a military party since he was the only former soldier in it.
He said he did not persuade Gen Prayut Chan-o-cha to join the party. "It's his decision to make," he said.
"I'm here because we want unity so we're strong enough to help people. We want to ensure coalition parties work together harmoniously."
To the criticism few soldiers who jumped into politics were successful historically, Gen Prawit said: "I've served the country for 50 years and have always solved the country's problems, only not as a politician."
While talking to MPs, he stressed the importance of full parliamentary attendance and said he would like MPs who held two positions to resign to give others a chance to perform MP duties in full.
He was referring to MPs on the party list who have been appointed ministers or held other political positions. If they resign as MPs, others next in line on the party list can take their places as MPs.