UN Secretary-General Ban Ki-moon with Susan Rice, the new U.S. permanent representative to the United Nations.(Xinhua photo)

Rice is the first African American to assume the U.S. ambassador to the United Nations as the new U.S. administration and the United Nations both vowed to work closely with each other to address major global problems, such as the Middle East peace process and the climate change.

U.S. President Barack Obama assured his "strong support" to the United Nations when Ban and Obama discussed major international issues in their phone talks last Friday.

She is with the U.S. Mission to the United Nations to succeed Zalmay Khalilizad, who served as the U.S. ambassador to the United Nations from 2007 to 2009.

She told the U.S. Senate Foreign Relations Committee on Jan. 14that she would work to strengthen the world body as an "indispensable if imperfect" institution.

"The UN is not a cure-all; we must be clear-eyed about the problems, challenges and frustrations of the institution," she said. "But it is a global institution that can address a tremendous range of critical American and global interests."

Confirmed by the U.S. Senate last Thursday, Rice is expected to help mend the rocky diplomatic marriage between the United States and the United Nations.

The Bush administration and the United Nations clashed repeatedly over the Iraq war. Obama signaled his intention to help improve ties by restoring the UN ambassadorship to Cabinet rank, the status it had during the Bill Clinton years.

Rice, 44, is not related to the former U.S. state of secretary, Condoleezz Rice, 54.

During the Clinton administration, Rice worked for the National Security Council and the State Department, primarily on issues related to Africa.