The Federal Aviation Administration announced that Frontier Airlines implemented a ground stop for all destinations, but lifted the order shortly thereafter.

IT issues at Frontier Airlines triggered a brief ground stop at all of the U.S. budget carrier's destinations on Thursday evening, according to an advisory from the U.S. Federal Aviation Administration.

Frontier Airlines has grounded all flights across the US due to IT issues, the FAA advisory says. Frontier Airlines serves over 100 destinations across the United States, Mexico, the Caribbean, and Latin America.

Frontier said in a release that it has met with Spirit’s board and executives since it made its proposal this month.

Spirit, which filed for bankruptcy protection last year, says it has rejected the new Frontier overture but would be open to a higher offer.

Frontier says a merger would be a better path out of bankruptcy for Spirit, as budget carriers struggle with high costs and competition.