U.S. Secretary of State Colin Powell has announced his resignation after four years of often futile policy battles with his hawkish colleagues over Iraq and North Korea.

A high-ranking State Department official said that President George W. Bush accepted the resignation of the former four-star general, who directed the 1991 war against Iraq but was only a lukewarm supporter of last year's invasion to oust Saddam Hussein. The official added, however, that Powell will continue to stay on until his successor is named.

U.S. media have speculated Bush's national security adviser Condoleezza Rice is the strongest candidate to succeed Powell.

Powell's resignation comes amid a Cabinet exodus that promises a starkly different look to Bush's second-term team.

Last week, the White House announced the departure of Agriculture Secretary Ann Veneman, Energy Secretary Spencer Abraham, Education Secretary Rod Paige, Attorney General John Ashcroft and Commerce Secretary Don Evans.