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 US and China.

The first two 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 Wednesday, Marshall Islands’ Foreign Minister Jack Ading gave an impassioned speech at a forum on the damage which nuclear testing had done to his country.

A day earlier, the forum host, Cook Island’s Prime Minister Mark Brown, said that recent decisions including the Japan’s release of treated wastewater from Fukushima into the Pacific and “increased surveillance of nuclear-powered submarines” had made nuclear issues more relevant to countries in the region.

“Pacific nations have concerns around these specific issues which is why we feel it’s appropriate that we should rediscover and revisit our Rarotonga treaty, to ensure it reflects the concerns of Pacific countries today,” he told reporters at a press conference.

The Treaty of Rarotonga, also known as the South Pacific Nuclear Free Zone Treaty, was signed in 1985 and is one of the signature achievements of the Pacific Islands Forum. It prevents the placement of nuclear weapons and the storage of nuclear waste across the South Pacific, among other restrictions. The US and China are not signatories, however Australia is.

Australia is in the process of purchasing a fleet of nuclear attack submarines from the US, before building its own vessels, as part of the AUKUS deal it signed with the US and UK in 2021.

The agenda of the Pacific Island leaders’ meeting is not released in advance but is already expected to include a push for faster action on climate change from developed nations. An anti-nuclear push and questions about AUKUS being added to the agenda would further complicate Albanese’s diplomacy.

Tess Cain, a Pacific expert at Griffith University, said she would be very surprised if the anti-nuclear discussion didn’t form a significant part of the summit’s final communique.

Cain said the discussion could be “problematic” for Australia, which will face “pointed questions” from its fellow Pacific leaders. “They have to walk this very careful line,” she said.

“There are Pacific policymakers who are looking at Australia saying, ‘Well, you know, where are you? Are you one of us?’”