LAS VEGAS — Nevada Republican Dean Heller has filed to run for re-election to the U.S. Senate, formally setting the stage for one of the country's highest profile Senate races in the midterm elections.

Heller is considered one of the most vulnerable Republicans running for re-election in the Senate this year. His seat is the only one up for grabs in a state carried by Democrat Hillary Clinton when President Donald Trump won in 2016.

Heller filed in Las Vegas on Friday, four days after first-term Democratic U.S. Rep. Jacky Rosen formally filed to run for his seat. Rosen announced her candidacy for Heller's seat last July.

Las Vegas Republican Danny Tarkanian also plans to challenge Heller in the GOP primary in June.