SAN FRANCISCO (KRON) — Imagine if international flights were no longer able to land at San Francisco International Airport, or other areas that were sanctuary cities, because the federal government pulled customs officers.

It’s an idea floated by the Trump administration’s new head of the Department of Homeland Security.

“Some of these cities have international airports. If they’re sanctuary cities, should they really be processing customs into their city?” said new DHS Secretary Markwayne Mullin. “If they’re a sanctuary city and they’re receiving international flights and we’re asking them to partner with us at the airport, but once they walk out of the airport, they’re not going to enforce immigration policy, maybe we need to have a really hard look at that because we need to focus on cities that want to work with us.”

Inaugural Southwest flight into Santa Rosa arrives at Sonoma County airport

Bay Area leaders were quick to clap back at this idea.

“This is just deranged,” said State Senator Scott Wiener, D-San Francisco. “It’s completely illegal. We would immediately challenge that in court. But would it create chaos if they decided to act on that? Yes, it would.”

Aviation experts say international carriers cannot be prevented from landing at SFO due to transnational agreements, but that’s not the case for U.S. carriers.

“Clearly, this is going to become difficult operationally for the airlines. It’s going to become a difficulty for the passengers,” said retired commercial airline captain Doug Rice.

Rice says if this proposal becomes reality, U.S. carriers could be forced to stop at non-sanctuary city airports to clear customs before continuing to airports like SFO.

“Anybody who has a connecting flight that was expecting to come off a non-stop flight with, let’s say, a two-hour connection in San Francisco is going to have difficulty if that airplane has to make an hour-and-a-half stop in Wyoming or North Dakota to clear customs, then proceed on to San Francisco,” Rice said.

That said, Rice is confident that pressure from the airline industry, pilot and flight attendant unions and passenger organizations will keep this proposal from taking flight.

Officials at SFO declined to comment at this time.

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