Republican Rep. Ann Wagner will not challenge Democratic Senator Claire McCaskill for her seat next year, Wagner announced Monday.

Instead, Wagner says she intends to run for re-election to the House, representing Missouri's 2nd District.

"Those who know me well know I put my family and my community first. While I am grateful for the incredible support and encouragement I have received from across Missouri to run for United States Senate, I am announcing today my intention to run for re-election to the United States House of Representatives in 2018," she said in a statement. "The 2nd District is my home. It's where I grew up, went to school, have worked and volunteered, raised my kids, and attend church every week – there is no greater honor than representing a place and people that I love."

In response, McCaskill's office released the following statement, "One politician has taken a pass, we're sure another politician will take her place."

Eyes across the nation are focused on McCaskill's seat, which is considered one of the most vulnerable seats for an incumbent Democrat nationwide, as Republicans work to maintain their Senate majority.

McCaskill has held the seat since 2006. In 2012, she was re-elected after challenger Todd Akin's campaign was derailed when he made controversial comments about "legitimate rape."