President Obama nominated Sen. John F. Kerry on Friday to be the next secretary of state, saying that “in a sense, John’s entire life has prepared him for this role.”

Kerry, a Massachusetts Democrat, chairs the Senate Foreign Relations Committee, and his selection all but guarantees a swift, smooth path to confirmation. The lawmaker has been a frequent foreign policy adviser and confidant to Obama, and his five terms in Congress have gained him bipartisan advocates in the Senate.

Kerry has long sought the post as America’s top diplomat. But he appeared to be Obama’s second choice after U.N. Ambassador Susan E. Rice. Rice withdrew her name from consideration this month because of Republican opposition based on her role as administration spokeswoman in the fatal Sept. 11 attack on the U.S. compound in Benghazi, Libya.

In a brief ceremony in the White House Roosevelt Room, Obama praised Kerry, the son of a U.S. diplomat, for his military service in Vietnam and his work decades later restoring diplomatic relations with that country, and for his long service in the Senate.

“He’s played a role in nearly every major foreign policy debate in the last 30 years,” Obama said.

Despite signals that Obama was likely to put forth nominees for two or more national security posts together, Kerry’s was the only name announced Friday. Former Republican senator Chuck Hagel of Nebraska, who has been the most prominent name mentioned as a candidate for defense secretary, has run into bipartisan opposition over his views on Iran, Israel and gay rights.

Kerry’s widely expected selection was announced at the White House with little fanfare. Only a small pool of reporters was allowed into the Roosevelt Room for the president’s remarks. Kerry did not speak at the lectern, and after a stiff handshake, Obama put a hand on Kerry’s arm and guided him out the door.

The two men are friendly but not especially close, colleagues and friends of both men have said. Obama joked that they had had a lot of forced togetherness earlier this year, when Kerry played the part of fellow Massachusetts politician Mitt Romney during the president’s debate practice.

“Nothing brings two people closer than weeks of debate prep,” Obama cracked.

Obama praised Kerry’s globe-trotting work ethic and noted his long list of personal relationships with leaders around the world. “He’s not going to need a lot of on-the-job training,” Obama said.

At the State Department, the senator would succeed Hillary Rodham Clinton, who has said she plans to leave at the close of Obama’s first term, although she has pledged to remain in place until a successor is confirmed.

Clinton had wanted to attend Friday’s announcement, Obama said. She remains at home under doctor’s orders following a fall and concussion more than a week ago. Obama said he had spoken to Clinton earlier Friday.

“She is in good spirits and could not be more excited” about Kerry’s selection, Obama said.

In a statement shortly after the announcement, Clinton called Kerry an uncommonly gifted and experienced public servant whose experiences in war and politics will serve him well.

“President Obama and I have often asked Senator Kerry to undertake delicate diplomatic missions and to deliver difficult messages,” Clinton said. “He has forged strong relationships with leaders around the world. As I have learned, being able to talk candidly as someone who has won elections and also lost them is an enormous asset when engaging with emerging or fragile democracies.”

That was a reference to her own failed contest against Obama for the Democratic presidential nomination in 2008 and Kerry’s loss as the party’s nominee against incumbent George W. Bush in 2004.

Obama noted his own political career was helped by Kerry, when the Massachusetts senator gave the then-Illinois state senator the keynote address at the 2004 Democratic National Convention. The speech helped launch Obama into the national arena.

If confirmed, Kerry would take over a department stretched by short budgets and rising security costs overseas, and a diplomatic corps still reeling from the killing of U.S. ambassador to Libya J. Christopher Stevens, a rising star whom Kerry knew well. But his experience in foreign policy has earned him the respect of many diplomats.

Kerry became a frequent emissary for the Obama administration overseas. He traveled to Afghanistan in 2009 and persuaded President Hamid Karzai to accept a runoff election.

The senator did similar work for the administration in Pakistan, where he helped broker the release of a CIA contractor arrested on suspicion of murder and later persuaded the Pakistanis to return parts of a U.S. stealth helicopter that crashed during the Abbottabad raid that killed Osama bin Laden. Kerry was also the first senior U.S. elected official to meet with Mohamed Morsi before and after Morsi became Egypt’s president.

For his confirmation hearing, Kerry would go before the Senate Foreign Relations Committee, the panel he has chaired since Vice President Biden departed the Senate in 2009.

The next-senior Democrat on the panel is Sen. Barbara Boxer (D-Calif.), but she said this week that she plans to continue chairing the Senate Environment and Public Works Committee. Aides confirmed that Sen. Robert Menendez (D-N.J.), the third-ranking Democrat on the committee, is poised to take over the Foreign Relations panel and chair Kerry’s confirmation hearing.

The White House has not said when it will announce other Cabinet picks, including for the Pentagon, but further announcements are most likely to wait until after the Christmas and New Year’s holidays.

Hagel issued an apology Friday for 1998 comments deriding a Clinton administration ambassadorial nominee as “openly aggressively gay.” Hagel said the remarks about James Hormel were insensitive.

“They do not reflect my views or the totality of my public record, and I apologize to Ambassador Hormel and any LGBT Americans who may question my commitment to their civil rights,” Hagel said, using the acronym for lesbian, gay, bisexual or transgendered people. “I am fully supportive of ‘open service’ and committed to LGBT military families,” Hagel added.

The Defense Department repealed its ban on openly gay military service two years ago.

Senior White House officials have contacted pro-Israel and gay rights groups, and some key Democratic senators, to gauge support for Hagel as mostly anonymous criticism of him mounted this week.

An activist group that pushed for repeal of the law known as “Don’t Ask, Don’t Tell” thanked Hagel but stopped short of endorsing him as Pentagon chief.

“We are pleased that Senator Hagel recognized the importance of retracting his previous statement,” said Allyson Robinson, an Army veteran and executive director of OutServe-SLDN.

Human Rights Campaign, the nation’s largest gay rights group, welcomed Hagel’s statement as evidence of “just how far as a country we have come when a conservative former Senator from Nebraska can have a change of heart on LGBT issues.”

Ed O’Keefe contributed to this report.