A mechanical issue caused former president Donald Trump’s plane to be diverted Friday as he headed to Montana for a rally, according to airport staff at Billings Logan International Airport.

The plane was scheduled to land in Bozeman, Mont., where his Friday evening rally is slated to take place, but instead landed in Billings, Mont., and Trump took another plane to Bozeman. The two cities are more than 100 miles apart.

At 5:30 p.m. Eastern, Trump released a video from inside a plane where he said he “just landed” in Montana but did not address the situation. Trump’s campaign didn’t immediately respond to a request for comment.

Trump is scheduled to hold a rally at 10 p.m. Eastern in Bozeman to boost Tim Sheehy, the Republican nominee for Senate. Sheehy is challenging Sen. Jon Tester (D-Mont.) in one of the country’s most closely watched Senate races. Minority Leader Mitch McConnell (R-Ky.) highlighted the race as key at a Friday event in Atlanta as Republicans try to win back control of the chamber in November.

This is a developing story that will be updated.