U.S. officials and key lawmakers on Capitol Hill are growing increasingly pessimistic about the prospects for bringing the bloody civil war in Syria to an end after the regime unleashed a new round of “barrel bombs” this week, killing civilians in the northern city of Aleppo.

Secretary of State John Kerry on Tuesday continued to condemn the “barbarity” of the bombings and reiterated the U.S. position that Syrian leader Bashar Assad must relinquish his hold on power.

“Each and every barrel bomb filled with metal shrapnel and fuel launched against innocent Syrians underscores the barbarity of a regime that has turned its country into a super magnet for terror,” Kerry said. “Given this horrific legacy, the Syrian people would never accept as legitimate a government including Assad.”

But the U.N.-led Syrian peace talks that ended in Geneva last week, where the two sides sat down and faced each other away from the battlefield for the first time, only seemed to heighten tensions between the opposition and the regime.

Amid growing frustration with Assad's delays in taking steps to destroy his chemical weapons stockpile as he pledged to do, U.S. intelligence officials say his regime has grown stronger since President Obama backed down from a threatened military attack last year over Damascus' alleged use of chemical weapons after Syria agreed to destroy its chemical stockpile.

James Clapper, the director of national intelligence, said Tuesday that Assad has strengthened his position over the opposition since last year.

“The prospects are right now that he is actually in a strengthened position than when we discussed this last year, by virtue of his agreement to remove the chemical weapons, as slow as that process has been,” Clapper told the House Intelligence Committee during a hearing.

“So if he doesn't go, in the absence of some kind of a diplomatic agreement ensuring from Geneva or follow-on discussions, I would foresee kind of more of the same, sort of a perpetual state of stalemate whether neither the regime nor the opposition can prevail,” he said.

Earlier this week, the Washington Post reported that Kerry in a private meeting with a group of senators conceded that the Geneva negotiating process hadn't delivered and expressed a desire to change strategies and spoke “favorably” about arming and training the opposition.

The article quoted Sens. John McCain, R-Ariz., and Lindsey Graham, R-S.C., two of the most vocal and ardent critics of the administration's Syria policy.

The administration's next Syria move is anything but clear, though White House press secretary Jay Carney this week insisted that Obama “absolutely” still believes in his policy.

Key lawmakers on the left and the right are expressing deep concerns about arming the rebels because of the infiltration of al Qaeda and other extremist groups who are fighting alongside the opposition but also attacking each other for dominance in different areas, creating even more chaos in Syria.

“The problem is who do you arm and what do you arm them with and whether that's going to come back and bite you in the future,” Sen. Dianne Feinstein, D-Calif., told the Washington Examiner. “I think it's a very unclear picture right now [with] a growing fanaticism of the opposition and these clashes between the groups.”

“I think it's just a very dangerous time right now,” she added.

Sen. Johnny Isakson, R-Ga., who sits on the Foreign Affairs Committee, called the turmoil and bloodshed in Syria “a human tragedy of untold proportions” but he said he didn't know what the U.S. should do to try to bring about its end.

“I support continuing to help the rebels as long as we know who the rebels are,” he said. “I think we waited too late to engage in Syria and we're paying the price for being late to the party.”

“We ought to do everything we can to bring it to an end and what those things are I don't know,” he concluded.

Feinstein said she is deeply disappointed that Assad is still trying to hang on to power in year three of a civil war that has killed 130,000 people.

“I would have hoped after 130,000 people being killed Assad would realize that his time has come and gone and the best thing he can do for his country is allow somebody else to come into the leadership position — and get these things solved and get his towns rehabilitated and get his people fed,” she said.

Responding to those comments, McCain said wishful thinking will not bring about an end to the continued “slaughter” in Syria.

“All these things are difficult and every day they are more difficult,” he said. “The fact is we could arm the good guys and we can make a difference but right now it is a continued slaughter and a shameful chapter in U.S. history.”

“With all due respect to Sen. Feinstein, it's really hard now but was it this hard three years ago? Of course not. And what did they want to do then? Nothing. So they are the ones responsible for the situation that we have today.”