The tiny Pacific nation of Kiribati has elected a new president, ending the 12-year rule of veteran climate campaigner Anote Tong, his office said Thursday.

The low-lying island nation's new leader is Taneti Maamau, who won a national vote held on Wednesday, the presidential office told AFP.

Unconfirmed figures gave Maamau, from the opposition Tobwaan Kiribati Party, 60 percent of the vote in the three-candidate field, with nearest rival Rimeta Beniamina on 38.5 percent and newcomer Tianeti Ioane trailing on 1.5 percent.

Maamau's predecessor Tong had to step down after completing the maximum of three presidential terms.

In that time he put Kiribati, a grouping of about 30 islands with a population of 100,000, at the centre of the global climate change debate.

He travelled the world pointing out that his homeland lies barely two metres (6.5 feet) above sea level and is in danger of being submerged by rising tides.

As recently as December, Tong was at a UN conference in Paris, lobbying world leaders charged with forging a breakthrough climate pact.

"We must never ever allow ourselves as a species, to leave anyone behind," he told AFP at the time.

Tong also developed a string of radical schemes designed to help his people cope if their homeland was swamped.

Some -- such as housing them on giant artificial floating islands with skyscrapers and resort complexes -- were attention-grabbing notions designed to stir debate on a difficult topic.

But he also pioneered the concept of "migration with dignity" -- training islanders mostly used to a fishing lifestyle to give them useful skills if they were forced to become climate change refugees.

He will retire from politics and is expected to continue his climate advocacy after stepping down.