US President Barack Obama has nominated veteran US senator John Kerry to replace Hillary Clinton as Secretary of State.
Mr Kerry is chairman of the Senate Foreign Relations Committee and was the Democratic presidential candidate in 2004.
President Obama called Mr Kerry the "perfect choice" for America's top diplomat as he began reshaping his national security team for a second term.
He expressed confidence that the Senator would win swift confirmation from his Senate colleagues.
Even Republicans in Congress said they expect Kerry, 69, to sail through the confirmation process, Reuters reports.
Last week front-runner Susan Rice, the US ambassador to the United Nations, withdrew from consideration amid scathing Republican criticism of her handling of the attack on the US consulate in Benghazi, Libya.
Mr Kerry will be the leading Cabinet member charged with tackling pressing global challenges, ranging from upheaval in the Middle East to Iran's nuclear standoff with the West and winding down the war in Afghanistan - all at a time of fiscal austerity at home.
He has sometimes served as Mr Obama's special emissary in times of crisis. He flew to Afghanistan in 2009, when he helped talk President Hamid Karzai into agreeing to a runoff election, and to Pakistan in 2011 amid an uproar over a US government employee who was arrested for killing two people allegedly trying to rob him.
But the president has centralized national security decision-making in the White House and analysts say Mr Kerry's selection could signal an even firmer White House hand in President Obama's second term.