Air traffic controller furloughs scheduled to kick in on Sunday could result in flight delays of more than three hours in Atlanta, as well as significant delays in Chicago, Los Angeles and New York-area airports, federal officials said Thursday.

Transportation Secretary Ray LaHood and Federal Aviation Administrator Michael Huerta said they have no choice but to cut controller staffing by 10 percent, which will reduce how many planes airports can handle. But a spokeswoman for Airlines for America, a trade association for the airline industry, said the furloughs are unnecessary and airlines are considering suing the government.

Without the furloughs, FAA officials could find no way to cut $637 million from the agency’s budget as required by automatic, across-the-board spending cuts approved by Congress, LaHood and Huerta said at a media briefing.