UNITED NATIONS - Starting his first day of work, new Secretary-General Ban Ki-moon vowed Tuesday to end mistrust of the United Nations and called for action to tackle “daunting” problems from crises in the Middle East and Darfur to reducing extreme poverty by half by 2015.

He renewed his promise to give priority to the North Korean nuclear issue and to defend human rights. When asked about Saddam Hussein's execution, he said the victims of his crimes must not be forgotten, but he stressed the need to strengthen the rule of law.

Ban also announced that his first overseas trip will be to attend the African Union summit in Addis Ababa, Ethiopia, on Jan. 29-30 and hopes to meet Sudan's President Omar al-Bashir there. He said he will meet his special envoy on Darfur, Jan Eliasson, on Wednesday and put “my highest attention on this” issue in hopes of resolving the conflict peacefully.