Nov. 15 (UPI) — President Donald Trump on Sunday called on Congress to approve new funding to build a new air traffic control system, two days after a nationwide ground stop halted all flights in the United States.

Trump and members of his administration pointed fingers at the aging airspace network owned and operated by L3Harris, saying it was time for a new, upgraded system.

“If Congress approves the desperately needed money for Air Traffic Control, we can get it built quickly and efficiently,” Trump said in a post on Truth Social. “It will be the BEST SYSTEM anywhere in the World. Much of our current air control system is 50 years old – RIDICULOUS! We have already started the work, but it should be done all at once, not in drips and drabs. Congress must approve. The Biden Administration set it back years!”

On Friday afternoon, the Federal Aviation Administration issued a full ground stop — the first since 2023 and, prior to that, since the Sept. 11, 2001, terror attacks — citing a telecommunications issue. Officials have yet to specify the exact cause of the telecommunications failure.

In an appearance Sunday morning on NBC’s Meet the Press, Transportation Secretary Sean Duffy said he wants to move air traffic control operations away from the company that owns the current system, Florida-based L3Harris. He said right now, though, that’s not possible.

“And the reason is that L3Harris, decades ago, got the contract to run and own the network that operates communication for the FAA,” he said.

In a Friday night press briefing, Duffy asked Congress for $50 billion to fund an entirely new network. He said Sunday that some companies have the architecture in place for such a network, including AT&T, Verizon and Lumen.

Sen. Chris Van Hollen, D-Md., took issue with the Trump administration blaming Congress for a lack in funding the updates needed. He said he would support any funding deemed “necessary,” but said the administration must justify the request before Congress.

“Unfortunately, Secretary Duff’s first response just the other day was to point fingers and blame Congress,” Van Hollen said in an appearance on CNN’s State of the Union on Sunday.

“Congress has met the Trump administration’s request, and it was the Republicans who in their so-called Big Beautiful Bill that put in the $12.5 billion of which they’ve only spent one-third.”

Friday’s ground stop led to more than 9,000 flight cancellations across the country Friday. The ground stop was lifted Friday evening, but the effects of the disruptions lingered Sunday. About 6,700 flights were canceled Saturday, and, as of Sunday midday, there were more than 1,800 cancellations in the United States, FlightAware reported, up from a daily average of about 170 a month prior.

The airport with the most affected flights — both arriving and departing — Sunday was Dallas-Forth Worth International Airport, with 10% of originating flights and 14% of arriving flights cancelled.