Hagel's nomination was approved by 58 votes to 41 in the US Senate on Tuesday.

Just four Republicans joined majority Democrats in approving the Republican former US senator and Vietnam War veteran.

Obama welcomed the "bipartisan confirmation," saying it allowed him to "have a defense secretary our nation needs and the leader our troops deserve."

"I will be counting on Chuck's judgment and counsel as we end the war in Afghanistan, bring our troops home, stay ready to meet the threats of our time and keep our military the finest fighting force in the world," the president said.

The vote came just hours after Republicans agreed to end tactics employed to delay his confirmation.

During an initial vote earlier this month Republicans launched a technique known as a filibuster to block a vote on his confirmation. They demanded more information on Hagel's finances and transcripts of speeches he gave to international organizations. It was the first time such a tactic had been employed to delay consideration of a nominee for defense secretary.

Republicans accused Hagel of being too mainstream, not sufficiently supportive of Israel and too lenient on Iran. Last month he faced sharp questioning from senators during a nomination hearing in which he was grilled over his record on defense issues.

The former Nebraska senator was blasted in questioning by Republican Senator John McCain for criticism of President George W. Bush's handling of the Iraq war.

Hagel, 66, is likely to be sworn in on Wednesday. He replaces Leon Panetta who served for four years as CIA director and Pentagon chief.

ccp/kms (AFP, Reuters, AP, dpa)