Reid: Republicans Blocking Hagel

"For the sake of our national security it is time for us to put aside political theater," Reid said.

The Nevada Democrat made an impassioned appeal for Hagel's confirmation amid questions over whether he could get the 60 votes needed to overcome roadblocks preventing a vote.

Reid accused Republicans of trying to score political points by coming up with one reason after another to delay confirmation of a new Pentagon chief, including for the first time ever using the blocking tactic known as a filibuster to prevent a vote.

If confirmed, Hagel would replace retiring defense secretary Leon Panetta.

Democrats, who have remained united in support of Hagel, a former Republican senator from Nebraska, control 55 seats in the 100-member Senate and could confirm Hagel without any Republican backing. A Cabinet nominee requires the support of only a simple majority to be confirmed.

However, they need the support of 60 senators to clear the procedural hurdles and allow the vote.

Hagel broke from his party as a senator by opposing former President George W. Bush's handling of the Iraq War, angering many of his Republican colleagues. Some members of his party have also raised questions about whether Hagel, 66, is sufficiently supportive of Israel, tough enough on Iran or capable of leading the Pentagon.

Earlier, two Republicans had said they would vote for Hagel and several others said they would oppose procedural hurdles, but those votes may not have held as bitter battling over Obama's nominee have continued.

A senior Senate Democratic aide said Republicans had informed Democratic leaders that there were not enough Republicans willing to join the Democrats to yield the 60 votes needed to allow the vote to go through.

A senior Republican aide said it was not clear if enough Republicans would cross the aisle to join the Democrats.

A White House spokesman said Obama still stands strongly behind Hagel, and said the "unconscionable" delay does not send a favorable signal to allies or U.S. troops.