White House press secretary Jay Carney on Tuesday slammed Russia, saying Moscow had offered an “unhelpful approach” to ending the Syrian civil war as the Geneva peace talks failed to provide a breakthrough.

“There is no question that we are all pained by what we see in Syria, and enormously frustrated by the obstructionism that the Syrian regime participates in, the unhelpful approach that Russia has taken on the Security Council when it comes to a resolution regarding humanitarian aid access,” Carney told reporters.

Carney's comments come amid mounting criticism of the Obama administration's handling of the Syrian crisis. Critics say that Russia has increased its support for Syrian President Bashar Assad, allowing him to stall negotiations toward a diplomatic solution and slow-walk compliance with an international agreement to relinquish his chemical weapons.

Russia has been Assad’s most staunch ally, blocking numerous Security Council efforts to pressure the Syrian strongman and provide assistance to opposition groups.

Moscow, though, insists that it is a fair broker between Damascus and rebel groups, a stance the White House dismissed.

“We should note that when it comes to the urgent need to allow for the provision of humanitarian assistance to the Syrian people, we have been working with partners on the United Nations Security Council to move forward on a resolution that would advance that cause, and Russia has been a holdout,” said Carney.

“If you're going to proclaim your concern about the fate of the Syrian people, one way to act on that concern is to not block progress in the United Nations Security Council on a resolution that would provide humanitarian assistance to the Syrian people, who so desperately need it,” he added.

The Obama administration has intensified its criticism of Russia in recent days, with Secretary of State John Kerry saying that Moscow's support had encouraged Assad to “double down” on a military victory.

Reports said that the intelligence chiefs of a number of Western and Arab powers opposed to Assad’s rule last week discussed efforts to provide more military assistance to Syrian rebel groups.

Carney on Tuesday said that it was “still our view absolutely that there is not a military solution to this conflict.”

“Negotiated political settlement is the only path forward for Syria, and the Geneva process is a process by which that is pursuable and achievable at this time,” he said.

But Carney conceded “there's no question that there has not been a great amount of progress” and that Obama would continue to review all U.S. options for ending the violence.

“It should not be forgotten that the obstacle to progress here has been the regime. The opposition attended the Geneva talks and conducted themselves appropriately,” said Carney. “The regime however has made clear that it is throwing up obstacles to moving forward and making progress.”