U.S. Democratic Party’s candidate, Mr Joe Biden, has finally picked his running mate for the Nov. 3 presidential election.

She is California senator, Kamala Harris, Biden announced in a tweet on Tuesday afternoon.

“I have the great honor to announce that I’ve picked @KamalaHarris, a fearless fighter for the little guy, and one of the country’s finest public servants, as my running mate.

“Back when Kamala was Attorney General, she worked closely with Beau.

“I watched as they took on the big banks, lifted up working people, and protected women and kids from abuse.

“I was proud then, and I’m proud now to have her as my partner in this campaign,” Biden tweeted.

Harris, 55, an Indian-American, is the first black woman and first person of Asian descent to be nominated for a federal office by a major political party in the U.S.

She is the fourth woman to be chosen for a presidential ticket in the country.

Harris contested for the ticket against Biden and was his fierce critic before dropping out of the race to later become a strident supporter of the former Vice President.

Biden’s announcement sparked immediate reactions from some political big wigs in the country, including President Donald Trump.

Trump tweeted a video clip showing moments where Harris criticised Biden during her campaigns, including referring to him as “not smart”.

Ms Susan Rice, a former National Security Adviser and one of those tipped to be chosen by Biden, issued a statement pledging her support.

“I am confident Biden-Harris will prove to be a winning ticket. I will do my utmost to help them win and govern,” she said.

Vermont senator, Bernie Sanders, who also contested for the ticket, congratulated Harris, saying she “will make history as our next Vice President”.

“She understands what it takes to stand up for working people, fight for health care for all, and take down the most corrupt administration in history.

“Let’s get to work and win,” Sanders said on Twitter.(NAN)