Homeland Security Secretary Markwayne Mullin said Friday, November 13, that a telecommunications outage affecting the Federal Aviation Administration's (FAA) systems caused the nationwide ground stop that halted departing flights across the United States.

Mullin said there was currently no reason to connect the FAA disruption to a separate Microsoft outage. However, he cautioned that investigators had not ruled out the possibility of a cyberattack or an issue involving Super Intelligence (SI) as the underlying cause.

The FAA ordered a nationwide ground stop after communications problems affected Air Route Traffic Control Centers across the country. The disruption forced airports to hold departing aircraft while officials worked to determine the source of the failure and restore normal operations.

Transportation Secretary Sean Duffy previously confirmed that FAA technicians were investigating the communications problem and promised updates as more information became available.

Mullin's comments leave open questions about whether the telecommunications failure resulted from a technical malfunction, an outside cyberattack or another systems-related issue. Officials have not publicly identified the precise cause of the outage.

The incident has renewed attention on the reliability and security of America's air traffic control infrastructure, which the Trump administration has been seeking to modernize through additional federal funding.