60-year-old Walz, currently governor of Minnesota, has a background as a national guardsman, among other things. Something that caused problems for him after an interview he did in 2018, where he said he had carried a weapon "in war", went viral.
The Harris campaign quickly announced that it was a misstatement, Walz took leave just before his unit was sent to Iraq in 2004. But the Trump camp has been hard on Walz and called him a liar.
In an interview with CNN, which he did together with Harris on Friday night Swedish time, Walz says that the statement about "carrying war weapons" was made in a context that dealt with a school shooting.
He emphasizes that anyone could have taken part in his background.
My CV has been public for 40 years, he says.
Tim Walz has been open about his and his wife's struggle to become parents, but has also received criticism for incorrectly saying that they had gone through an IVF treatment – when in fact they had a child with the help of insemination.
Walz says that he wishes he didn't have to be open about his fertility problems because, as he says, "it's hell".
I talked about the treatments that were available to us. It's a big contrast to the people who are trying to take those rights away from us, he says.
He also claims that Republicans are looking for things to criticize.
If it's not this, then it's an attack on my children for showing me love, or an attack on my dog, he says.