Shortly after his swearing-in as defence secretary, Chuck Hagel has said the US should engage with the world rather than dictate to it.
Mr Hagel told Pentagon employees that the US must lead with its allies.
He made the remarks a day after the Senate approved his appointment following a bruising nomination battle.
Also on Wednesday, the Senate intelligence committee delayed a vote on whether to approve President Barack Obama's nominee for CIA director.
Mr Hagel was confirmed by a 58-41 vote after Republicans stalled his nomination, questioning his past positions on Israel and Iran and his qualification for the job.
He replaces Leon Panetta, who was confirmed unanimously in June 2011.
Use resources 'wisely'In 15 minutes of remarks at the Pentagon, Mr Hagel called for the US to continue building strong relationships with old and new allies.
"We can't dictate to the world, but we should engage with the world," said the nation's 24th defence secretary.
End QuoteHagel has stirred up a sudden storm in a chai glass here, with past suggestions that India has been using Afghanistan as a 'second front' against its old rival Pakistan"
He added that the US was a "force for good" and that the US military should use its resources around the globe "wisely".
The former Republican Nebraska senator arrives at the Pentagon two days before $46bn (£30bn) in across-the-board cuts are set to hit the military.
On the budget cuts, Mr Hagel thanked staff for working to figure out how to deal with the reductions. But he said the real danger was the "uncertainty of planning, the uncertainty of commitment".
The new defence secretary also said he was committed to making sure that both US troops and civilian workers were treated fairly and equitably.
Two weeks ago, Republicans delayed a vote on Mr Hagel's confirmation.
But they dropped the filibuster stalling tactic, the first time it had ever been used to delay confirmation of a defence secretary, on Tuesday after a week-long recess.
President Barack Obama's Democratic Party holds a 55-45 edge in the chamber, and Mr Hagel ultimately only needed 50 votes to be confirmed in the final vote.
Republican Senators Thad Cochran, Rand Paul, Richard Shelby and Mike Johanns voted in favour of Mr Hagel's appointment.
Also on Wednesday, the Senate intelligence committee delayed a vote on White House counter-terrorism adviser John Brennan, whom Mr Obama has nominated as the next director of the CIA.
The panel's top-ranking Republican, Senator Saxby Chambliss, said a vote would be rescheduled for Tuesday but did not explain why it had been delayed.
Meanwhile, some Democrats have expressed concern over the government's use of unmanned drones to carry out "targeted killings", and have suggested a vote on Mr Brennan should be delayed until the committee can review certain secret documents relating to the programme.