(NewsNation) — Vice President Kamala Harris has been interviewing some of the contenders to be her running mate in the 2024 election, NewsNation has learned.

Once she picks her potential vice president, two sources with knowledge of the matter said, Harris is expected to campaign with them in battleground states. Reuters was the first to report on this plan. According to the publication, the battleground states include Michigan, Pennsylvania and Wisconsin.

While sources confirmed to NewsNation that the interviews are being done by Harris’ team, they did not say how many the presumptive Democratic nominee for president has conducted or who they were with.

Harris’ running mate announcement is reportedly expected before Aug. 7.

Who will Kamala Harris choose for vice president?

Ever since it was announced that current President Joe Biden was stepping out of the 2024 election, there’s been speculation about who Harris’ running mate would be.

Rising on Harris‘ short list is Minnesota Gov. Tim Walz, who has been praised by fellow Democrats for his affable persona and experience as chair of the Democratic Governors Association. 

“I think Walz is making a strong case,” one Democratic source told NewsNation. Walz told CNN’s “State of the Union” on Sunday that even being mentioned is “certainly an honor.”

Others somewhere on the Harris campaign’s list include Democratic Governors Josh Shapiro of Pennsylvania, Kentucky’s Andy Beshear and JB Pritzker from Illinois. Arizona Sen. Mark Kelly and Transportation Secretary Pete Buttigieg‘s names have also been floated.

Two people who are not going to be Harris’ running mate include Governors Roy Cooper of North Carolina and Michigan’s Gretchen Whitmer, both of whom withdrew themselves from consideration.

NewsNation digital producer Devan Markham and Reuters contributed to this report.