Papua New Guinea's prime minister Peter O'Neill will ask his Australian counterpart Tony Abbott for the return of three Australian Manus Island security guards to face questioning over rape allegations.

In July, three private security guards were flown off Manus Island amid allegations they raped a local woman working at the detention centre.

PNG police said the men and a local woman were found naked, drunk and sniffing an unidentified substance on the night before the security guards left PNG.

Mr O'Neill said the return of the men to face questioning would be one of the issues discussed when he meets Mr Abbott on Thursday on the sidelines of the Pacific Islands Forum (PIF).

"They must face up to the allegations and see if they can be tried in the normal rule of law in Papua New Guinea," Mr O'Neill said at a press conference.

In 2013, PNG amended its sentencing laws to extend the death penalty for rape convictions.

"That's our laws, we can't break our laws," Mr O'Neill said.

Mr Abbott will also face calls from Pacific leaders to do more to tackle climate change at the forum.

On Tuesday, Kiribati president Anote Tong warned Australia could be asked to leave the PIF if it did not start supporting stronger action to reduce emissions.

Pacific nations are also expected to call for a ban on new coal mines and more ambitious targets for limiting global temperature rise.