Parnpree quit on Sunday after he was stripped of his dual position as deputy prime minister in Srettha’s Cabinet reshuffle.
The prime minister apologised to his fellow Pheu Thai Party member Parnpree and thanked him for his contribution since the coalition government took office last August.
He said the two had known each other for 10 years and have been close friends.
"I want to focus on the good relationships we've had over the past 7-8 months. Parnpree has been beneficial to the nation since he assumed his position. I believe the new minister who will replace him will continue this legacy,” said Srettha.
He added that Phumtham, deputy PM and commerce minister, would take over as acting foreign minister until Parnpree’s successor had been vetted by the selection committee. He did not name the incoming foreign minister, saying only that the candidate has experience in diplomacy and politics, as well as a background working behind the scenes for Pheu Thai.