Tonga's King King Tupou VI will open the first session of the Legislative Assembly of Tonga this morning.

Clerk of Tonga's Parliament Gloria Pole'o said the King's address will be delivered through a livestream feed from his residence on the island of 'Eua to the parliamentary chambers in Tongatapu where Members of Parliament and invited guests will gather to receive the opening address.

Ms Pole'o said the first parliamentary session will be the following day on Thursday.

"At this meeting the newly elected members will take their respective oathes of office as Members of Parliament and as ministers of the Cabinet and these oaths will be taken in the presence of the Assembly," she said.

Gloria Pole'o said Thursday's meeting will include the election of chairman of the House Committee.

The reply to the Speech from the Throne is also expected to be tabled at Thursday's meeting and needs to be approved by the House before it is submitted to the King.

Last month, King Tupou has presented Tonga's newly elected Prime Minister, Siaosi Sovaleni with a Royal Warrant of Appointment in Nuku'alofa.

Mr Sovaleni was elected as Designate Prime Minister by 16 members of the 26-members parliament in a secret ballot earlier this month.

He will hold the office of Prime Minister for four years.