Australia’s prime minister is likely to face some pointed questions over climate action and a nuclear submarine deal on Thursday, as a growing number of Pacific nations push to strengthen a signature anti-nuclear treaty.

Australian leader Anthony Albanese is beginning 24 hours of intensive meetings between the leaders of the Pacific Islands Forum at the atoll of Aitutaki in the Cook Islands. Only leaders or delegates of the 18 forum nations are allowed to attend, excluding representatives from the U.S. and China.

The first three days at the forum have displayed growing concern from Pacific Island nations over some of the key nuclear policy issues facing the region. At an event on Wednesday, Marshall Islands’ Foreign Minister Jack Ading gave an impassioned speech on the damage that nuclear testing had done to his country.