A university spokesman says Puna officiated at the event in his role as the 23rd Chancellor of USP.
The graduation ceremony saw more than 130 graduates receive their Masters, and Bachelors’ degrees as well as diplomas and certificates.
The Tonga Broadcasting Commission (TBC) said it was Puna’s first official visit to the Kingdom of Tonga in his capacity as USP chancellor.
Puna received an audience with His Majesty King Tupou VI and Tongan prime minister Akilisi Pohiva.
Kaniva News said 75-year-old Lea’aetoa ‘Ofakihevaha Fatai received a Certificate in Early Childhood Education, making her the oldest graduate in Tongan USP history.
Fatai was a former Tongan government primary school teacher who taught mostly at Pangaimotu, Vava’u.
Students at USP have to study the programme full time. Previously it could be completed within one year or in one and a half years if participants studied part time.
Graduates received their certificates after a morning street procession along Taufa ‘hau Rd in Tongatapu.
Puna was installed as Chancellor of USP during a graduation ceremony at Laucala campus in Fiji earlier this year.