John Bolton has resigned as ambassador to the United Nations, ending a controversial 16-month term. In August 2005, Bolton was given a temporary recess appointment after he failed to be confirmed by the Senate. Last month, President Bush renominated Bolton, but a number of Democratic and Republican senators announced they would not back his confirmation.

President Bush: “I received the resignation of Ambassador John Bolton. I accept it. I’m not happy about it. I think he deserved to be confirmed. And the reason why I think he deserved to be confirmed is because I know he did a fabulous job for the country.”

One top contender to replace Bolton is reported to be Zalmay Khalizad, the U.S. ambassador in Iraq.