BEIRUT -- A U.S.-supported push to form military councils across Syria to unite the hundreds of groups fighting to topple President Bashar Assad and coordinate the provision of aid to secular rebel groups appears largely to have failed.

Rebels said U.S. officials pressed for the creation of the councils in each of Syria’s 14 provinces in response to rebel demands for arms and other support. In December, representatives of various rebel groups met in Turkey and elected a 30-member Supreme Military Council, which then selected defected Syrian Gen. Salim Idriss as its head.

But Syrian activists say the councils have become the subject of derision and mockery inside Syria in the weeks since and that other groups, including the al Qaida-linked Nusra Front, have assumed the central coordinating position that U.S. officials had hoped the military councils would have.

“I do not hear much about the military councils,” said Jeff White, a military analyst with the Washington Institute for Near East Policy. “I also do not see yet any indication the Supreme Military Council or regional commands are doing anything yet.”

Members of the military councils have blamed the United States and other nations for failing to provide support, saying that without aid, the councils were unable to gain influence over the fighting inside Syria.

“They had this plan, but no one received any support,” said Mahmoud, a Syrian-American who has set up a small rebel training camp in northern Syria and says he receives support from individual donors. He asked that his full identity not be revealed because of security concerns.

U.S. officials in Washington on Monday continued to voice support for the anti-Assad opposition.

"I think we’ve seen the opposition in Syria make continued progress,” White House spokesman Jay Carney told reporters. “I think we’ve seen Assad’s grip on power in Syria continue to lessen. We continue to take steps with our partners to provide both humanitarian aid and non-lethal assistance to the opposition and to work with our partners to help bring about a post-Assad Syria that reflects the will of the Syrian people, because the right outcome here is for the Syrians to decide their own future."

The failure of the military councils to quickly organize and win influence has undercut what U.S. officials had hoped would be a system that would allow the United States and its allies to direct aid toward rebel groups that favor a democratic post-Assad Syria, where the rights of religious and ethnic minorities would be respected, and away from groups such as Nusra that favor a government based on Islamic law.

But Islamist groups remain at the forefront of recent fighting, while the military councils are barely functioning. That’s true throughout the country, including the south, where more than 20,000 people fled fighting into Jordan last week alone.

Syria’s presumed government in exile, the Syrian National Coalition of Revolutionary and Opposition Forces, similarly has failed to take hold – another huge reversal for American policy. U.S. Secretary of State Hillary Clinton had been the primary proponent of the coalition, which was cobbled together after Clinton publicly announced that the United States could no longer support a predecessor group, the Syrian National Council.