Funafuti, Tuvalu: Scott Morrison has vowed not to shy away from the "tough conversations" with Australia's regional "family" as his New Zealand counterpart Jacinda Ardern warned his government "will have to answer to the Pacific" on climate change.

The Prime Minister is facing increased pressure at the Pacific Islands Forum in Tuvalu to sign up to a tough statement from 18 nations calling for a global transition away from coal.

Children symbolically representing climate change greet Prime Minister Scott Morrison as he arrives for the Pacific Islands Forum in Tuvalu. Credit:AAP

The Morrison government has worked furiously behind the scenes to convince counterparts to tone down the language of the draft Funafuti Declaration, arguing any reference to a transition away from coal-fired power was a "red line" issue for Australia.

Mr Morrison, who was greeted by children submerged in a wading pool pleading for action on arrival in Tuvalu on Wednesday, said Australia was going to "show up" to the two-day leader's retreat, where he has promised Australia would be a "champion" on environmental issues in the Pacific region.