By David Shepardson

WASHINGTON United Airlines Chief Executive Scott Kirby met on Tuesday with the acting head of the Federal Aviation Administration (FAA), officials told Reuters, after he blasted its air traffic control performance last month.

Kirby in a June 26 in a memo to employees expressed frustration "the FAA frankly failed us this weekend... We estimate that over 150,000 customers on United alone were impacted this weekend because of FAA staffing issues and their ability to manage traffic."

Kirby met with Acting FAA Administrator Polly Trottenberg, who has been on the job since June 8, the sources said. In remarks at a Politico forum on Tuesday, Kirby struck a new tone, saying the FAA had been "particularly helpful, responsive and communicative" in the last two weeks.

"It's been the best two weeks that we've ever had," he said.

Kirby added the FAA responded well to thunderstorms on Sunday that forced cancellation of about 30% of New York-area airline flights, including at its Newark hub.

"They deserve a lot of credit for what they have been doing the last few weeks because they're 54% staffed in New York and to have that event be managed and contained was some heroic efforts," Kirby said.

Asked about Trottenberg's previously unreported meeting with Kirby, an FAA spokesperson declined to confirm or deny the meeting but said the agency "will always collaborate with anyone seriously willing to join us to solve a problem." United declined to comment on the meeting.

The FAA is experiencing serious air traffic control staffing issues, notably in New York. A government audit said staffing issues pose risks to the continuity of air traffic operations. U.S. airlines, including United, have urged more air traffic-control hiring.

Kirby said in a separate July 1 memo after severe weather forced additional flight disruptions that it would reduce flights in Newark. "Newark has more flights scheduled than the physical infrastructure can handle," Kirby said on Tuesday.

Kirby said in that memo he had recent "constructive conversations" with Transportation Secretary Pete Buttigieg and the FAA.

He also apologized on June 30 for taking a private jet home during severe weather saying it "was the wrong decision because it was insensitive to our customers who were waiting to get home."

(Reporting by David Shepardson; Editing by Jamie Freed)