The White House made it official Monday: President Bush will nominate Zalmay Khalilzad to be the U.S. envoy to the United Nations and Ryan Crocker to replace him as U.S. ambassador to Iraq.
Both changes were revealed in news reports last week.
Secretary of State Condoleezza Rice made the announcements on Monday.
Khalilzad, who is Afghan born, has also served as ambassador to Afghanistan. He will replace John Bolton, who could not win Senate confirmation and resigned last month as his temporary appointment as U.N. ambassador was about to expire.
Crocker, a veteran American diplomat who is now U.S. envoy to Pakistan, will replace Khalilzad in Baghdad.
Bush is shuffling his teams of military and diplomatic advisers as he plans to announce a new Iraq strategy on Wednesday.
Gen. John Abizaid, the top U.S. commander overseeing the theater that includes Iraq, will be succeeded by Adm. William Fallon, now Abizaid's counterpart in the Pacific. Army Lt. Gen. David Petraeus is the president's choice to be the new chief commander in Iraq, replacing Gen. George Casey.
Casey in turn will replace the retiring Gen. Peter Schoomaker as Army chief of staff.
Bush has also decided to shift John Negroponte, the national intelligence director, to the State Department to become No. 2 to Rice. Replacing Negroponte would be retired Vice Adm. Mike McConnell, a veteran of more than 25 years in intelligence.