FCC Commissioner Ajit Pai said Friday the agency has "fallen behind" on a 2010 pledge to free up spectrum for the wireless industry.

"The Commission has fallen behind schedule in meeting the goals set forth in the National Broadband Plan," Pai said in a copy of a Friday speech before the U.S. Chamber of Commerce in Washington, D.C.

The FCC vowed to free up 300 MHz of spectrum for mobile broadband by 2015 and a total of 500 MHz by 2020, but so far has made little progress on the ambitious initiative. The wireless industry has lobbied hard for the Commission to act on its promise as operators scramble to address a spectrum shortage.

"So far, in the two and a half years since the plan was released, we haven’t made any additional spectrum available for wireless broadband use," Pai said.

Pai said he sees "no realistic prospect" that the FCC will act this month on Dish Network's request to open 40 MHz of AWS-4 satellite spectrum for terrestrial wireless service, but he is "optimistic" the necessary rules will be in place by October "if we make it a priority."

The FCC is under the gun to follow through on key initiatives ahead of the November elections. On Friday, it will vote on a proposal to move forward with voluntary selloffs of additional television broadcast spectrum to commercial wireless providers. It is unclear how much spectrum will become available through the incentive auctions.

Pai has not been shy about taking a stand on high-profile issues since taking his post in May. He expressed skepticism about a July government report advocating federal users share spectrum with the commercial wireless industry and has criticized the FCC's decision to halt deregulation of the special access market.

In his speech, he pushed the Commission to address regulatory uncertainty by making its suggested 180-day deadline on transaction reviews mandatory, not merely a goal. He also pushed for faster turnaround time on license renewal requests and called for clarity on "ambiguous" statutes and regulations.