UN Secretary-General Ban Ki- moon on Wednesday extended "his warm congratulations" to Susan Rice on her appointment as the U.S. national security adviser.

Rice, who was appointed by U.S. President Barack Obama to be the next national security advisor Wednesday and had been serving as U.S. Permanent Representative to the UN since 2009, has been "a strong voice in the Security Council and an effective advocate on the full range of issues before the UN, from peace and security to human rights and development," Ban said in a statement issued here by his spokesperson.

The UN chief appreciated "the dynamic role" that Rice has played and welcomed "the firm commitment she so often demonstrated, in particular to African issues and on matters such as women's empowerment," said the statement. "The Secretary-General looks forward to continued cooperation with Susan Rice in her new capacity, and to welcoming her successor to the UN."

Rice will replace Tom Donilon whose resignation as National Security Advisor was made known Wednesday. Obama also nominated in the same day Samantha Power, a former national security staffer, to be the next U.S. ambassador to the United Nations. The nomination of Power needs the approval of the U.S. Senate. Endi