PORT MORESBY – Australia Opposition Leader Bill Shorten says he is touring the Pacific region to investigate the impact of climate change.

Shorten arrived in Papua New Guinea with his Deputy Opposition Leader Tanya Plibersek and immigration spokesman Richard Marles on Sunday.

He said he wanted to show that a Labor government would take the concerns of Pacific nations more seriously than the current government.

“The message I’m already getting loud and clear is that climate change is a first order issue for our neighbours and we need Australia to have serious policies, credible policies which will help to contribute to mitigating the effects of climate change in our region,” he said.

The leaders of some Pacific island nations have criticised the Australian government’s response to climate change, and expressed offence when Immigration Minister Peter Dutton joked about its impact on Pacific countries.

But Shorten said his trip was a fact-finding tour, not an attempt to exploit tension between the Pacific and the current government.

“Having Liberal Ministers making a joke about climate change, especially when rising sea levels are threatening the livelihoods and homes of our neighbours, was incredibly poor taste,” he said.

Australia’s relationship with the Pacific, especially over the issue of climate change, was damaged in September when the immigration minister, Peter Dutton, was picked up by a boom mic joking about climate change with then prime minister Tony Abbott.

Pacific leaders excoriated the minister. The Marshall Islands’ foreign minister, Tony de Brum, said he was “dismayed” by the “insensitivity of the big polluting island down south”.

PNG prime minister Peter O’Neill said the comments were unfortunate, and Kiribati’s president, Anote Tong described the joke as “vulgar”.

“As long as there is this kind of attitude, this kind of arrogance in any position of leadership, we will continue to have a lot of tension,” Tong said.

Shorten will fly to the Marshall Islands from Papua New Guinea and will also visit Kiribati later in the week.

Australia should “tell the story of the Pacific to the world” when global leaders sit down to climate change talks in Paris at the end of this month, Labor has said.

Shorten and his entourage will depart Papua New Guinea for the Marshall Islands and then Kiribati during this week’s four day tour.

The Labor leaders said climate change was an existential threat to some countries in the region.

“The dangerous consequences of climate change is no more evident than in the Pacific region. Pacific leaders have consistently identified climate change as the greatest threat to their livelihoods, food production, housing, security and well-being.

“This is a serious problem that demands serious attention,” Marles, the former parliamentary secretary for Pacific island affairs, told Guardian Australia.

He said it was important for Australia to have strong and constructive relations with its Pacific neighbours. He praised Pacific leaders, in particular Kiribati’s president, Anote Tong, for highlighting the issues being faced by Pacific nations on the international stage.

“It is crucial that, in the lead-up to Paris, the world understands the problems being faced by the Pacific. And it’s important that Australia plays a role in telling that story of the Pacific to the world.”

- PNC sources