Washington DC - New Department of Homeland Security Secretary Markwayne Mullin has threatened to stop processing international travelers at airports in "sanctuary cities."

During a press conference on Tuesday, Mullin argued that cities that refuse to enforce immigration laws, which have become known as "sanctuary cities" for undocumented people, are not legal, and said drastic measures should be taken.

"If cities are ​going to sit there ​and say that ⁠they're not going to enforce immigration policies, then I'll repeat myself and say it doesn't make any sense for us ​to process international travelers through that city," Mullin said.

The proposal comes after President Donald Trump appointed Mullin – a former senator of Oklahoma and longtime MAGA ally – to head DHS after ousting former Secretary Kristi Noem last month.

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Mullin had aggressively pushed the idea of defunding sanctuary cities long before gaining his new role. In July 2025, he argued that "not a single federal dime" should go to such cities, and in February 2026, he went as far to say the government should "pull our TSA agents out of their airports and not allow their airpot to be classified as international or even a regional hub."

In an interview with Fox News on Monday, Mullin asked if sanctuary cities should "really be processing customs?"

According to Reuters, Mullin's proposal could halt international air travel and commerce at major airports in Democratic states across the country, severely impacting trade and tourism.