Missouri Secretary of State Jason Kander launched a Democratic challenge Thursday to U.S. Sen. Roy Blunt by criticizing the Republican's long political career and asserting  that "it's time for a new generation of leaders" in Washington.

Kander, a former Army captain who served in Afghanistan, highlighted his military service while announcing his candidacy in an online video and asserted in an interview with The Associated Press that Blunt is often "on the extreme edge of a lot of issues."

Kander, 33, is Blunt's first prominent opponent for the 2016 election. If Kander is elected, he would be one of the youngest U.S. senators -- an attribute that he said should be a positive during a campaign.

"Missouri has a senator who's been in Washington for nearly 20 years and has been running for one political office or another for over 40 years. For too long, he's been a part of the problem," Kander said in his video announcement.

He added: "I believe it's time for a new generation of leaders, who have come of age at a time of unprecedented challenges and threats to our country, and who are committed to bringing people together and doing what's right, no matter what the personal cost."

Blunt won election to the Senate in 2010 after serving for 14 years in the U.S. House. He was Missouri's secretary of state from 1985-1993 and served as the Greene County clerk from 1973-1985.

Kander was elected as secretary of state in 2012 after serving four years in the Missouri House. He was in the Army for eight years and said he was spurred to join by the Sept. 11, 2001, terrorist attacks. While serving as an Army intelligence officer, Kander said he volunteered to be deployed to Afghanistan in 2006. He filmed his candidacy announcement from a passenger waiting area at the Kansas City airport, where he said he departed for his service in Afghanistan.