Closer international cooperation is necessary to help Pacific island nations combat the impact of climate change, UN Secretary-general Ban Ki-moon said on Wednesday, pledging the United Nations' commitment to mitigating the problem.

"No other challenge in the Pacific is as urgent and potentially life-threatening as climate change," the secretary-general warned in a message to the leaders attending the Pacific Islands Forum in Port Vila, Vanuatu.

The message was delivered by Thomas Stelzer, assistant secretary-general for policy coordination and inter-agency affairs of the UN Department of Economic and Social Affairs (DESA).

In his message, Ban encouraged the Pacific nations to maintain "engagement at the highest level" with the UN High-level Advisory Group on Climate Change Financing. The secretary-general established the group in February to study potential sources of revenue that can be used to help developing countries carry out activities to mitigate and adapt to climate change.

This is particularly important because a summit on the UN's Millennium Development Goals (MDGs) is slated for mid-September at the UN Headquarters in New York, Ban said, adding that the gathering "will start our final push for the goals over the next five years."

The MDGs are a set of enumerated and time-bound targets for tackling social and economic ills such as poverty, illiteracy and HIV/AIDS, all by 2015.

The secretary-general pointed out in his message that the situation in the region is especially important to the entire international community because "resettling whole populations outside national boundaries is under consideration."