"They are filibustering him. That's what they're doing. I'm going to go call Chuck Hagel when I finish here and say, 'I'm sorry, sorry that this happened. I'm sorry for the president, I'm sorry for the country and I'm sorry for you, but we're not going to give up on you,' " Reid said on the Senate floor.
Reid, who switched his vote from 'yes' to preserve his ability to bring up the nomination again, vowed to hold another vote when the Senate returns to business.
"I hope, I really, really do hope, that nothing happens in the next ten days that we won't have a secretary of Defense," he said. "If this is not a filibuster, I'd like to see what a filibuster was. The first time in the history of our country that a secretary of Defense has been filibustered successfully, and probably ever filibustered," he added.
The majority leader went on to blast his Republican colleagues blocking the nomination after having had multiple hearings on Hagel's qualifications to lead the Defense Department.
However, Sen. John McCain (R-Ariz.) argued that it was "appropriate" to wait until the Senate returns for the vote.
“I think there’s plenty of time to have any further questions answered and I intend to vote for cloture then. ... He’d certainly get mine and a number of others," McCain said.
Meanwhile, President Obama called Thursday's vote "unfortunate" during a Google Plus Hangout, and said that Hagel had been consistently praised by Republicans as a senator and was “imminently qualified” for the post.
Despite the contentious nomination process, Hagel appears likely to eventually win confirmation.
Read more on Hagel's blocked nomination on The Hill's DEFCON Hill blog.