A spokesman for Sen. John McCain of Arizona, the ranking Republican on the Senate Committee on Armed Services, said McCain would hold up Dempsey's nomination to a second term "until he gets answers to the legitimate questions he asked of General Dempsey on Syria," the Los Angeles Times reported.
During a hearing Thursday, McCain asked Dempsey about the possibility the United States might carry out airstrikes to back rebels in the Syrian civil war. Dempsey said the Pentagon has plans for "direct kinetic strikes" and President Barack Obama is considering military options, but declined to say what he thinks on the question of U.S. use of force.
"Do you think we ought to see how we could stop the war by intervening and stopping the massacre?" McCain asked.
Dempsey said he would "let this committee know what my recommendations are at the appropriate time, yes, sir."
He said use of force is "a decision for our elected officials, not for the senior military leader of the nation."
Dempsey rejected McCain's suggestion he has been inconsistent in his public statements on use of force, saying administration policy changes based on "what we know of the opposition."
Sen. Joe Donnelly, D-Ind., asked what steps the United States could take, short of a no-fly zone, against the regime of Syrian President Bashar Assad.
Navy Adm. James Winnefeld, nominated for reappointment as vice chairman of the Joint Chiefs of Staff, said there are "a whole range of options that are out there," but added he did not want to "get into any intelligence community judgments or anything classified in an unclassified hearing."
The Obama administration has said it will provide rebels with weapons and ammunition but has ruled out sending U.S. ground troops to Syria, and Obama has said a no-fly zone would be difficult to establish and execute.
White House press secretary Jay Carney told reporters Thursday the United States is "providing a broad range of assistance to the Syrian opposition."
"And as I've said I think several times this week, we cannot detail every single type of support that we are providing, but all of our assistance is provided in consultation with the opposition leadership," he said.
Dempsey told the committee if the Pentagon does not manage the transition to lower defense spending imposed by congressional sequestration "our military power will become less credible," USA Today reported.
"Even as dollars are in decline, risk is on the rise," Dempsey said.
The nation's defenses are "already out of balance" because of the cuts, Dempsey said.
"But it's not too late to recover," he added. "Remove the budget uncertainty. Slow down the drawdown. Help us make seemingly intractable institutional reforms."
Sen. James Inhofe, R-Okla., said during the hearing that while the defense budget represents 18 percent of the federal budget, it had incurred 50 percent of the cuts required by mandatory across-the-board reductions for all federal agencies.