MAJURO, MARSHALL ISLANDS (AFP) - The Pacific Islands Forum leadership rift widened on Sunday (Feb 7) as the Marshall Islands voiced its disapproval with the central political body in a region where the United States and China are competing for influence.

Palau has already announced it was pulling out of the organisation and would meet the Marshall Islands and other Micronesian members of the forum on Monday to discuss what has been described as "a huge fracture" in regional unity.

The row erupted last Thursday, when the Micronesian candidate to be the organisation's next secretary-general was rejected in favour of former Cook Islands premier Henry Puna, after a virtual meeting of leaders from the 18-member body.

The five Micronesian states - Palau, the Marshall Islands, Kiribati, Nauru, and the Federated States of Micronesia - had argued it was their turn to fill the post under an informal arrangement that has stood for decades.

"We need to reassess our relationship with the PIF. They ignored the 'gentlemen's agreement' and we can't take it any longer," Marshall Islands Foreign Minister Casten Nemra said.

The PIF is made up mostly of small Pacific island states along with Australia and New Zealand, and is a key element of the US allies' diplomatic efforts in the region.

However, any division in the forum's ranks could provide an opening for China to boost its influence with the sparsely populated but strategically important nations.

Micronesian nations have long felt their north Pacific island states have been neglected in favour of their larger and more influential neighbours in the south.

"What we have seen is a south Pacific that looks down on the north Pacific and we find that deeply unfortunate," Federated States of Micronesia President David Panuelo told Australian radio in the wake of the leadership vote.

"It's a huge fracture in the (forum's) unity and spirit of cooperation."

Marshall Islands opposition MP David Paul pressed for his country to follow Palau and withdraw, saying that to do nothing would make them "the laughing stock of the forum, and our (Micronesian) neighbours won't trust us".

However, Foreign Minister Nemra indicated there could be other courses of action.

"We shouldn't pull out, but we must review our participation," he said.