Uber says tens of thousands of Seattle travelers walk out of Seattle-Tacoma International Airport each month and pull out their phone to hail a ride — only to realize that’s the only place where they can’t use the apps they rely on to get around every day.

The company — which has butted heads with local governments across the country — says it has been told for months that new rules to eliminate exclusive taxi agreements were on the way in Seattle. But now it’s tired of waiting.

“It is indefensible that TNC [transportation network company] drivers, like those operating on our uberX platform, are uniquely unable to pick up passengers at Sea­Tac —­ even as those same drivers safely drop off thousands of passengers at Sea­Tac every week,” Uber’s Seattle general manager Brooke Steger wrote in a letter to the port commissioners that was obtained by GeekWire on Wednesday.

The letter didn’t indicate that Uber will begin defying the ban, like fellow ride-sharing company Lyft has done in the past, but it did demand immediate change.

“Now is the time for the Port of Seattle to permit TNC operations, and provide the transportation options and level of service that riders expect,” Steger wrote.

Update: The Port of Seattle responded to GeekWire’s request for comment regarding the letter on Wednesday afternoon, saying the organization is looking at a range of options right now and is “optimistic” it will reach an agreement soon. Here is the Port’s complete statement:

“The priority of the Port of Seattle is to provide excellent customer service to the traveling public. Current ground transportation options serve the public with a variety of pre-arranged and on-demand services for travelers. The port is looking carefully at new agreements with a range of transportation services including traditional metered cabs, flat-rate cabs, limousines and the app-based TNC’s such as Uber and Lyft. At the same time the Port of Seattle Commission has the responsibility to provide fair and comprehensive services addressing the needs of travelers within the physical constraints of the airport’s roadways and transportation infrastructure. Balancing those interests is a challenge for Sea-Tac and many other airports around the nation. We are optimistic we can reach an agreement soon.”

This week’s letter marks the latest escalation in what has been long-running debate. Lyft and Uber are allowed to drop off passengers at the Seattle airport, but can’t pick up riders because of an existing contract that only allowed Yellow Cab to pick up arriving travelers. That deal, which required the cab company to pay a minimum of $3.67 million or 13 percent of its gross revenues from airport pickups, expired in October.

The Port Commission, which controls the regulations, met in both May and September to discuss changes that would allow Uber and Lyft at the airport, but the ban still remains in place today. Uber has gone so far as to hire outside taxi services to pick up users who request rides at the airport, but that’s just a temporary fix.

In the letter, Uber says the ban often forces drivers who drop customers off at the airport to drive back to Seattle without any passengers. That costs them money, Uber money, and the city money since the company would be contributing a portion of revenues like every other taxi service at the airport.

Now is the time for the Port of Seattle to permit TNC operations, and provide the transportation options and level of service that riders expect.

“For months, the Commission and Port administration have told Uber that it was just a matter of time until pick­ups were authorized ­­— that an agreement was just around the corner,” the letter reads. “Unfortunately, both staff and the Commission have delivered that same message several times: an agreement would be finalized in April, then June, then August, then October at the latest. October has now passed, and we appear no closer to a resolution. Instead, we are told to tell drivers and riders that they need to wait yet again.

Here is Uber’s complete letter to the Port of Seattle commissioners.