The Trump campaign announced Thursday that the president will hold a rally at the Bemidji airport Friday, Sept. 18, at 4 p.m.

The Biden campaign said the former vice president will travel to Minnesota the same day, and said details about when and where will be announced later.

Northern Minnesota is a key battleground in the fight for the state’s 10 electoral votes. Trump came within about 45,000 votes of carrying Minnesota in 2016 and has made winning the state a priority this time.

The Trump campaign is trying to build on his support in greater Minnesota and the outer Twin Cities suburbs, while Biden is counting on strong Democratic turnout in the Twin Cities and inner suburbs. The president last campaigned in Minnesota on Aug. 17 in Mankato. This will be Biden’s first campaign stop in the state since December 2017.

No Republican has carried Minnesota since 1972. But Trump’s team is increasingly confident about his chances. His campaign sent Donald Trump Jr. and Lara Trump to Minnesota this week, while the Biden campaign sent Jill Biden.