US President Barack Obama on Friday nominated Senator John Kerry as his new secretary of state, as he began to reshape his national security team for a second term clouded by increased global turmoil.
Kerry, 69, a decorated Vietnam War veteran, defeated former presidential candidate and foreign policy sage, will succeed Hillary Clinton, who is stepping down after four years as the top US diplomat.
"Over these many years, John's earned the respect and confidence of leaders around the world," Obama said at the White House as he announced Kerry's nomination, his first second-term cabinet pick.
"He is not going to need a lot of on the job-training."
"I think it's fair to say that few individuals know as many presidents and prime ministers or grasp our foreign policies as firmly as John Kerry."
Kerry stepped up following the withdrawal of UN ambassador Susan Rice, the early favorite for the post, who was caught in the political aftermath of the attack of the US consulate in Benghazi, Libya in September.
Obama said that Kerry, chairman of the Senate Foreign Relations committee, had played a central role in every US foreign policy debate for 30 years and that his "entire life" had prepared him for his new role.
Kerry saw life overseas as the son of a Cold War foreign service officer, served as a navy officer in Vietnam, and spent years wrestling with foreign policy issues in the Senate.
Obama said that Clinton had hoped to be at the announcement, but was still recovering from a serious virus and a concussion.
The White House had hoped to make a clean sweep by announcing all nominations to the national security team, including new chiefs of the CIA and Pentagon at once.
But a crush of political events, including the "fiscal cliff" economic crisis, has pushed them back. A battle is already raging as opponents seek to tar former senator Chuck Hagel, a possible pick for Defense Secretary.
Kerry, who is well known abroad after acting as an unofficial envoy for Obama, is expected win easy confirmation from his Senate colleagues.
In the past years Kerry has traveled to the Middle East and South Asia, and met Syria's President Bashar al-Assad several times as Washington mulled a diplomatic opening. He also sought a renewal of Arab-Israeli peace talks before the outbreak of the Syrian revolt.
In May 2011 Kerry went to Pakistan to try to ease tensions after the killing of Osama bin Laden, and in February 2009 he made a rare visit to the Hamas-ruled Gaza Strip, without meeting anyone from the Islamist group.
As soon as he is confirmed in his new job, Kerry will face a huge array of foreign policy challenges, including a critical moment in the Iranian nuclear showdown and what could be the last throes of the Assad regime in Syria.
Kerry's Senate colleagues welcomed his appointment.
"We have known John Kerry for many years. We have confidence in John Kerry's ability to carry out the job," said Senator John McCain.
"I think John Kerry was a very solid choice by the president," said Republican Senator Lindsey Graham, who however noted he had some policy disagreements with Kerry.
Kerry played an important role in Obama's political career, notably by picking him to give the keynote speech in the 2004 Democratic convention, at which the then unknown Illinois lawmaker burst onto the political scene.
He also played Republican presidential candidate Mitt Romney in mock debates staged by the president's team ahead of Obama's successful re-election effort in November.
"Nothing brings two people closer together than weeks of debate prep," Obama quipped.
Kerry narrowly lost the 2004 presidential race to president George W. Bush, after a campaign that included savage attacks on his war service.
He was lambasted by Republicans who accused him of "flip flops" on the Iraq war, and the Bush campaign ran an ad showing him windsurfing, with the kicker "John Kerry, whichever way the wind blows."
Kerry will be the first white, male secretary of state for years, following three women -- Clinton, Condoleeza Rice and Madeleine Albright -- and Colin Powell.
Kerry first shot to prominence in April 1971 when he testified to the Senate committee he would later lead, and famously asked: "How do you ask a man to be the last man to die for a mistake?"
Earlier, during his second 48-day tour in Vietnam, Kerry was awarded three Purple Hearts, a Bronze Star and a Silver Star for valor for his work as a lieutenant in charge of dangerous "Swift" gunboat missions in the Mekong Delta.