King Tupou VI has officially appointed 'Akilisi Pohiva as Prime Minister of Tonga.
Mr Pohiva was re-elected as Prime Minister in November.
Tonga's constitution states the King has to appoint the Prime Minister-Designate for the election to come into effect.
Mr Pohiva was re-elected by the Legislative Assembly in a 14 to 12 vote following the snap election in November.
Mr Pohiva served as Tonga's 16th Prime Minister from 2015-2017 before the King dissolved Parliament following concerns about the government's conduct.
The long-time democracy campaigner is Tonga's longest-serving active Member of Parliament and first took a seat in 1987.
The Prime Minister is expected to formally announce his Cabinet line-up in the coming week.