HONIARA, Solomon Islands: United Nations chief Ban Ki-moon says he has seen firsthand the need for urgent action on climate change after visiting the remote Solomon Islands.

During his one-night stay, Ban said rising sea levels are wiping out crops on low-lying islands in the Solomons and threatening the existence of the entire chain, located 1,200 miles (1,930 kilometers) northeast of Australia.

Ban said Sunday that he’s ready to ‘‘sound alarm bells to the whole world’’ over the dangers of climate change. He said the developed world has a moral obligation to help nations like the Solomons with financial and technological aid.

Ban was due to leave Sunday for Kiribati, another island chain threatened by climate change. From there, he’ll fly to New Zealand.