WASHINGTON: President Barack Obama on Friday nominated Sen. John Kerry as his next secretary of state, elevating the longtime lawmaker and foreign policy expert to the top diplomatic job he had coveted.    

''He is not going not need a lot of on-the-job training,'' Obama said, standing alongside Kerry at the White House. ''Few individuals know as many presidents and prime ministers or grasp our policies as firmly as John Kerry.''

If confirmed by the Senate, Kerry would replace Secretary of State Hillary Rodham Clinton, who plans to leave Obama's second-term Cabinet early next year.

Clinton, who is recovering from a concussion sustained in a fall, did not attend the Roosevelt Room announcement.

The 69-year-old Democrat is expected to be easily confirmed by his Senate colleagues. He would be the first of what are expected to be several new faces on Obama's national security team, including a new defense secretary and director of the Central Intelligence Agency.

The son of a diplomat, Kerry has served as chairman of the Senate Foreign Relations Committee and is a decorated Vietnam veteran who was critical of the war effort when he returned home to the United States.

He has represented Massachusetts in the Senate since 1985.

''John's entire life has prepared him for this role'' said Obama, who praised Kerry for his belief that the country must harness ''all elements of Americans power.''

The president picked Kerry for the post even though his nomination could create a political problem in Massachusetts.

Republicans are eying the Senate seat Kerry will vacate after five terms, and recently defeated GOP Sen. Scott Brown would be a favorite in his party for the job.

Kerry's nomination could bring to a close what has become for the White House a contentious and distracting effort to find a new secretary of state.