Telecommunications companies AT&T and Verizon have both rejected regulatory calls to temporarily delay the rollout of their respective 5G wireless services. The Federal Aviation Administration reportedly asked the companies to hold off on launching their services due to aviation safety concerns.

The CEOs of both companies rejected the requests for a delay. U.S. Transportation Secretary Pete Buttigieg and FAA chief Steve Dickson reportedly asked the two companies to delay their rollout for at least two more weeks. AT&T and Verizon previously set a Jan. 5 launch of their respective 5G networks. 

In a joint letter sent out on Sunday, the two companies said they rejected any broader limitations to the launch of their new C-Band high-frequency spectrum networks, which are being used for their respective 5G services. The companies assured regulators that they would not be deploying any of their 5G towers near airports for the next six months. However, both wireless companies offered little information on their plans to adopt safety protocols.

The FAA and several international aviation regulatory bodies have raised concerns over the potential interference of 5G networks with sensitive aircraft systems and signals like radio altimeters that might negatively affect pilots' abilities to fly their airplanes safely.

Last week, the FAA recommended selecting priority airports where a buffer zone would let aviation operations continue safely while the FAA completes its evaluations of the interference potentially caused by 5G signals. Airline unions have expressed support for the FAA's proposal.

Airlines for America, which represents American Airlines, FedEx Corp., and other airlines, petitioned the Federal Communications Commission last week to prevent the deployment of 5G networks near major airports, citing the risk of thousands of flights being severely interrupted. The airline group has stated that it would go to court if there were no actions taken by regulators.

AT&T and Verizon, which recently won the C-Band spectrum in an $80 billion government auction, had previously committed to the gradual implementation of their 5G networks to limit interference and to allow regulators enough time to assess potential negative effects on commercial flights.

The two wireless providers said in their joint letter that the FAA's latest proposal is "irresponsible" and would further delay their offering the American people of world-class communications networks. The companies said their so-called exclusion zones in airports in France had found no such interferences. The CEOs said the laws of physics in France and the U.S. should be the same, and if flights remain undisrupted every day in France, then the same should be true in the U.S.