Donald Trump’s running mate Ohio Sen. JD Vance stepped up his attacks on Minnesota Gov. Tim Walz’s portrayal of his military career, accusing him of ducking service in Iraq when he left the Army National Guard and ran for Congress in 2005.

Vance also accused Walz of falsely claiming he had served in a combat zone while the Democratic vice presidential nominee was in the Army National Guard.

While Walz retired two months before his unit received alert orders to deploy to Iraq, the attacks on Walz’s military record are part of the race from both parties to define the relatively unknown governor after he was tapped Tuesday as Vice President Kamala Harris’ running mate. Walz’s 24-year military service is one of several facets of his background that appeal to voters that the Harris campaign is trying to reach with his selection – and that Republicans are trying to blunt by painting him as an out-of-touch liberal.

Walz and Vance, the two VP candidates, are both military veterans, unlike their running mates.

Walz served in the Army National Guard for 24 years before retiring in 2005. He launched a campaign for Congress in Minnesota’s 1st Congressional District that year and was elected in November 2006.

At a campaign stop in Michigan on Wednesday, Vance accused Walz of abandoning his unit before it deployed to Iraq in 2006.

“When the United State Marine Corps, when the United States of America asked me to go to Iraq to serve my country, I did it. I did what they asked me to do, and I did it honorably and I’m very proud of that service. When Tim Walz was asked by his country to go to Iraq, you know what he did? He dropped out of the Army and allowed his unit to go without him,” Vance said.

Walz filed paperwork with the Federal Election Commission as a candidate for Congress on February 10, 2005. The next month, after the guard announced a possible deployment to Iraq within two years, Walz’s campaign issued a statement saying he intended to stay in the race.

“I do not yet know if my artillery unit will be part of this mobilization and I am unable to comment further on specifics of the deployment,” Walz said in the March 2005 campaign release.

“As Command Sergeant Major I have a responsibility not only to ready my battalion for Iraq, but also to serve if called on. I am dedicated to serving my country to the best of my ability, whether that is in Washington DC or in Iraq,” he continued, adding: “I don’t want to speculate on what shape my campaign will take if I am deployed, but I have no plans to drop out of the race. I am fortunate to have a strong group of enthusiastic supporters and a very dedicated and intelligent wife. Both will be a major part of my campaign, whether I am in Minnesota or Iraq.”

Walz retired from the Army National Guard in May 2005, according to the Minnesota National Guard. In a 2009 interview for the Library of Congress, Walz said he left the guard to focus full time on running for Congress, citing concerns about trying to serve at the same time and the Hatch Act, which limits political activities for federal employees.

Service members often submit their paperwork for retirement months before their retirement date. It’s unclear when Walz submitted his papers for retirement.

The Harris campaign did not immediately respond when asked about when Walz submitted his retirement paperwork.

A National Guard article on his unit’s deployment states that it received alert orders to deploy to Iraq in July 2005, two months after Walz retired. The unit first mobilized in the fall of 2005 to Camp Shelby Mississippi to prepare for deployment, according to the unit’s history, and then deployed in March 2006 for 22 months, which the Guard said was the longest continuous deployment of any military unit during US operations in Iraq.

In his comments Wednesday, Vance also went after Walz for claiming he had served in combat, accusing the governor of being “dishonest” with his claims about his service.

“He said that we – and he was making a point about gun control – ‘shouldn’t allow weapons that I used in war to be on America’s streets,’” Vance said of Walz.

Vance pointed to a video promoted by the Harris campaign on social media Tuesday, in which Walz is speaking about his decision to change his position and support an assault weapons ban after the Parkland shooting in 2018.

“We can make sure that those weapons of war, that I carried in war, is the only place where those weapons are at,” Walz said in the video.

Walz deployed with the Minnesota National Guard in August 2003 to Vicenza, Italy, as part of support for the US war in Afghanistan, according to a Minnesota Guard spokesperson. He did not deploy to Afghanistan or Iraq or a combat zone as part of his service.

In a statement, a Harris campaign spokesperson said: “In his 24 years of service, the Governor carried, fired and trained others to use weapons of war innumerable times. Governor Walz would never insult or undermine any American’s service to this country – in fact, he thanks Senator Vance for putting his life on the line for our country. It’s the American way.”

Vance served four years in the Marine Corps as an enlisted combat correspondent, in public affairs, and deployed once to Iraq for roughly six months, according to his military record. He left service in September 2007 as a corporal.

White House press secretary Karine Jean-Pierre pushed back against Vance’s criticisms when asked about them Wednesday.

“This is someone who enlisted at 17 years old to serve his country. He was part of the Army National Guard for 24 years. This is someone who was a high school teacher, right?” Jean-Pierre said. “A high school coach as well, who grew up in a small town in the Midwest, and so I think his bio speaks for itself, who he is speaks for himself, his record speaks for itself, and I’m just not going to say anything beyond that.”

This is not the first time there have been criticisms of Walz’s military record. The Minnesota governor was criticized for his exit from the National Guard in 2022 by his Republican opponent, who held a press conference with veterans in the final stretch of the campaign, according to the Star Tribune.

At the time, Walz defended his service.

“We all do what we can. I’m proud I did 24 years,” Walz told the Minnesota paper. “I have an honorable record.”

The criticisms of his military record from within the state during his gubernatorial campaigns also focused on his rank when he retired.

Walz reached the rank of command master sergeant, but he officially retired as a master sergeant— one rank below command sergeant major — because “he did not complete additional coursework at the US Army Sergeants Major Academy,” according to the Guard.

Joseph Eustice, a 32-year veteran who led the same battalion as Walz, told the Star Tribune in 2022 that Walz did nothing wrong when he left the Guard.

”He was a great soldier,” Eustice said. “When he chose to leave, he had every right to leave.”

This story has been updated with additional reporting on the timeline of Walz’s service and information on his unit’s possible deployment to Iraq.

CNN’s Edward-Isaac Dovere and Natasha Bertrand contributed to this report.