“There's no question so far that the talks have not produced significant breakthroughs,” White House press secretary Jay Carney said.
“We recognize that significant progress is not being achieved,” he added.
Neither the Syrian opposition nor Assad’s regime have expressed optimism about a solution emerging anytime soon. In the meantime, the civil war there has claimed more than 136,000 lives and displaced millions more.
United Nations mediator Lakhdar Brahimi gave a dismal assessment of the ongoing negotiations.
"We expected that the talks would be difficult,” he said. "We didn't expect that [all sides] would be unable to compromise on an agenda, and that frankly is not good. That's a very bad omen for the process.”
After initially hailing a deal to disarm Assad's stockpile of chemical weapons, President Obama has expressed growing pessimism about peace in Syria.
"We still have a horrendous situation on the ground in Syria — I don’t think anybody disputes this,” Obama said in a press conference this week, adding that “we are far from” achieving a political solution to the violence.