Washington, Aug 4 (IANS): US Vice-President and Democratic Presidential nominee Kamala Harris is meeting three finalists for her running mate for a chemistry test on Sunday, taking the search into the final stage.

She is scheduled to announce her pick at a rally in Philadelphia on Tuesday.

Harris is expected to use these one-on-one meetings to test personal chemistry between her and her pick, who, if the ticket wins, will be her deputy for four years and another four years, if they are re-elected.

The other key qualification is governance - whether they will be ready to step in for her when needed. The finalists are the Governors of Minnesota and Pennsylvania, Tim Walz and Josh Shapiro, respectively, and Senator Mark Kelly.

It was not immediately clear if invitations had gone out to others in the fray - Kentucky and Illinois Governors, Andy Beshear and J.B. Pritzker, respectively, and Transportation Secretary Pete Buttigieg.

Roy Cooper, the Governor of North Carolina, took himself out of the race last month.

Presidential candidates usually take months to pick their running mate, but Harris has had to wrap up the search within weeks after her elevation to the top of the Democratic ticket on July 21 when President Joe Biden ended his re-election bid under pressure from within the party and endorsed his deputy.

Former Attorney General Eric Holder has done the vetting of the candidate along with a team of lawyers, going through reams of documents to prepare the shortlist for Harris to pick from. Holder gave the Vice-President a presentation at her home in the Naval Observatory on Saturday.

Harris has no rallies on her schedule for the weekend to wrap up the search and make the most important decision as the presumptive nominee. Walz, the Minnesota Governor, has emerged as a popular choice with his folksy style and ties to trade unions. He is a former school teacher who served as a member of the House of Representatives for several terms. He has impressed Democrats also for first using the word "weird" for the Republican nominee, former President Donald Trump, and his campaign, which has been embraced by the Harris campaign and Democrats up and down the party hierarchy.

Shapiro, the Pennsylvania Governor, has been seen as the top contender given his popularity in the state, which is a critical state for Harris to win to get to the White House. The two-term state Attorney General won the Governor's race in 2022 by nearly 15 percentage points; Harris currently trails Trump in the state by 2.7 percentage points in the RealClearPolitics average of polls.

Kelly is also from a key battleground state, Arizona, and could help Harris reach the 270 electoral college votes she needs to make history as the first woman to become US President - Harris trails Trump by 4 percentage points in this state. As a former fighter pilot and astronaut, he brings unique attributes to the ticket. And he is married to former Congresswoman Gabrielle Giffords who retired from politics after she was nearly killed by a gunman in 2011.