U.S. President George W. Bush has chosen National Security Adviser Condoleezza Rice to be his new secretary of state.

If confirmed by the Senate, Rice would be the first African-American woman to serve in the top Cabinet position.

The tapping of Rice for the job came a day after Colin Powell announced his resignation on Tuesday.

In announcing his nominee for the top diplomatic post, President Bush said that in Rice, the world would see "the strength, the grace and the decency of our country."

The 50-year-old Rice is considered more of a hard-liner than the moderate-minded Powell, who was often out of step with more hawkish members of Bush's national security team.

She joined the Bush presidential campaign in 2000 as a senior foreign policy adviser after six years as provost of Stanford University in California.

Bush also chose Deputy National Security Advisor Stephen Hadley to succeed Rice.