US Defence Secretary Robert Gates is expected to leave the Pentagon by the end of June, and President Barack Obama plans to nominate CIA Director Leon Panetta to replace the long- serving military chief, the White House said.
In a conference call arranged by the White House, a senior administration official told reporters that Obama will announce changes to his cabinet on Thursday, dpa reported.
The president will also name General David Petraeus, commander of US and international forces in Afghanistan, as the next CIA director, the official said.
Ryan Crocker, a retired diplomat who last served as US ambassador to Iraq, will be appointed ambassador to Afghanistan, the official said. The official said Petraeus will be replaced by Lieutenant General John Allen, deputy commander of US Central Command, which oversees military operations in the Middle East, South Central Asia and part of Africa.
All of the nominations require Senate approval.