The Pacific region is mourning the passing of a man who has been hailed for his fight for democracy in the Kingdom of Tonga.

 Prime Minister, 'Akilisi Pohiva, has died.  Aged 78, he passed away in Auckland, New Zealand.

The Prime Minister's death was confirmed to the Samoa Observer by a spokeswoman at the local Ministry of Information on Thursday. 

Mr. Pohiva was taken for emergency treatment to Auckland last night for treatment for liver problems, Radio New Zealand had reported.

"My condolences for a good friend and principled leader," the Foreign Minister of Vanuatu, Ralph Regenvanu, said in a statement posted to Twitter. 

Mr. Pohiva had been Prime Minister since 2014. He was the country's longest-serving Member of Parliament having been elected in 1987 and often clashed with authorities before his later elevation to the leadership.

In a long political career he served as a Minister for Health, Minister for Education and Training, Minister for Internal Affairs and Minister for Foreign Affairs.

He was remembered on Thursdsay as a pro-democracy campaigner who campaigned over three decades for greater democratisation in the country. 

Local news outlet Matangi Tonga reported that a sitting of Parliament had been indefinitely suspended following news of the Prime Minister's death. 

Before entering politics, Mr Pohiva had taught history and sociology at the Tongan Campus of the University of the South Pacific. 

He was married to Neomai Pohiva and had seven children.