Story highlights One airline industry source told CNN the DHS aviation security measures will be "seen and unseen"

The measures will not include an expansion of the laptop ban

Washington (CNN) Homeland Security Secretary John Kelly announced new aviation security measures Wednesday impacting overseas airports that have direct flights to the United States.

Speaking to the Center for New American Security, the DHS chief said if airline carriers refused to follow any of the new security measures they could be banned from operating direct flights to the US.

"The threat has not diminished. In fact, I am concerned that we are seeing renewed interest on the part of terrorist groups to go after the aviation sector," he said Wednesday.

Kelly's announcement comes as a "watered down" version of the Trump administration's long delayed travel ban will come into effect at 8 p.m. ET Thursday.

Unless they are able to demonstrate a "close relationship" with a US person or entity, people from Libya, Syria, Iran, Somalia, Yemen and Sudan are banned for 90 days.

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