CIA director Leon Panetta will become the new US defense secretary, while General David Petraeus will replace him, in a major shakeup of President Barack Obama's security team, ABC and NBC television reported Wednesday.

Panetta is to replace Defense Secretary Robert Gates, who has said he plans to step down later this year.

The television networks reported that Petraeus, the commander leading military operations in Afghanistan, will be replaced there by Lieutenant General John Allen, who currently is deputy head of US Central Command.

Meanwhile Ryan Crocker, a former US diplomat who served as ambassador in Pakistan and Iraq, will replace Ambassador Karl Eikenberry in Kabul.