Chuck Hagel sworn in as defense secretary (VIDEO)

Chuck Hagel was sworn in as the next secretary of defense after a difficult nomination fight, taking his oath of office at the Department of Defense on Wednesday. 

Hagel was confirmed in a hearing on Tuesday in a 58-41 vote, with only four Senate Republicans supporting President Barack Obama's nominee, ABC reported.

Republicans had delayed the confirmation vote, but on Monday GOP lawmakers said they would no longer stall the process, the Associated Press reported. 

GlobalPost analysis: For Hagel, now the hard part begins

"I am honored that President Obama and the Senate have entrusted me to serve our nation once again," Hagel said in a statement on Tuesday. "I can think of no greater privilege than leading the brave, dedicated men and women of the Department of Defense as they perform vital missions around the globe."

Hagel is expected to address Department of Defense employees later today, the AP reported.

ABC News has video of Hagel addressing the Pentagon: