The U.S. Senate foreign relations committee has unanimously approved Senator John Kerry's nomination to be secretary of state, BBC News reported.

The full Senate is expected to confirm his nomination later on Tuesday, January 29.

President Barack Obama chose the Massachusetts Democrat to succeed Hillary Clinton, who is stepping down after four years, as his top diplomat.

A Vietnam veteran and senator since 1985, Sen Kerry was the Democratic presidential candidate in 2004.

He first came to national attention as part of his involvement with Vietnam Veterans Against the War.

Sen Kerry's nomination is part of Mr Obama's second-term cabinet reshuffle. Former Senator Chuck Hagel, Mr Obama's pick for secretary of defense, will face a confirmation hearing later this week.