The Pacific island nation of Kiribati is moving towards authoritarianism, its former president said in an interview on Wednesday, after the government suspended all judges from its appeal and high courts.

Kiribati withdrew from the regional bloc, the Pacific Island Forum, in July, with China denying it had influenced the decision by the tiny atoll nation amid tensions between Beijing and Washington over the Pacific region.

Kiribati switched diplomatic recognition from Taiwan to Beijing in 2019, and struck economic and infrastructure deals when China's foreign minister visited in May.

The Kiribati government suspended three judges sitting on its court of appeal this week, after they ruled against the government's attempt to deport an Australia-born high court judge who is married to the leader of the opposition party.

Former president Anote Tong said the situation was "unprecedented" for Kiribati, which he said had been one of the most stable governments in the region.

"Kiribati is going through quite a serious constitutional crisis. Not to accept the decision of the court would suggest that we may be moving towards a certain state of authoritarianism," Tong said in an interview in Sydney.

Kiribati's government did not respond to a request for comment.

Tong, and the former president of Palau, Tommy Remengesau Jr., are in Australia representing the Pacific Elders Voice, a group of former leaders raising awareness of the threat of climate change to low-lying Pacific islands.

Tong welcomed the climate change policies of the new government in Australia, which has pledged to reduce emissions by 43% by 2030, but he said more was needed, including action on coal, one of Australia's largest exports.

Pacific islands are pushing for a resolution at the United Nations General Assembly this month that would direct the International Court of Justice to examine the threat climate change poses to future generations.

"When you talk about climate change, its not just economic or just livelihoods - it is the way of life, the traditions, the culture, the people who are impacted the most," said Remengesau in the interview.

Pacific island leaders, including Kiribati's, have been invited to meet U.S. President Joe Biden in Washington on Sept. 28-29, the latest effort by Washington to step up ties with the region increasingly courted by China.

Remengesau said climate change had to be the priority issue for the Biden meeting.

"Lets not forget climate change because of the jostling for other military or security concerns," he said.

A tuna treaty between the United States and Pacific islands, for which Washington has pledged to triple funding and boost maritime surveillance across vast Pacific fishing grounds, would have "a significant impact on the revenue situation of most of the countries involved", Tong said.

"I don't know if it's a response to the Chinese initiative but nevertheless it's welcome," he said, referring to a failed attempt by China to sign a trade and security deal with Pacific islands in May.