Pohiva Tu'i'onetoa has been officially appointed prime minister of Tonga by King Tupou VI.
He replaces late Prime Minister 'Akilisi Pohiva, who died in office last month.
The King was overseas when Parliament elected Mr Tu'i'onetoa Prime Minister last week
He returned to the kingdom on Friday, and made the official assignment on Tuesday.
Mr Tu'i'onetoa joined Tonga's civil service in 1979. He was trained in accounting and business management, and worked as the Auditor General until his election to Parliament in 2014.
He was appointed by 'Akilisi Pohiva as the Minister of Finance and National Planning in 2017.
The new prime minister is also the Minister of Foreign Affairs and Trade, and has taken over as the Minister of Public Enterprises.
His cabinet ministers are expected to be given royal confirmation in the coming days.
With Mr Tu'i'onetoa, they will form the government for the next two years until the general election in 2021.