The former South Korean foreign minister has been certain to win reelection for several months.

Ban, 67, declared his candidacy two weeks ago and was given formal backing by the UN Security Council on Friday. With no challenger to force a contest, the 192-member General Assembly will confirm the new term by consensus.

"There has never been any doubt," said one UN ambassador. "He may not be everyone's favourite but no one has any reason to stop him."

Ban said climate change -- a topic the United Nations struggled with during his first five years -- is his top challenge. He has called the battle against global warming "the most important priority" for mankind.

AFP