Joe Biden hailed Elizabeth Warren as “the fiercest of fighters for middle class families” after she decided to suspend her presidential campaign, while seemingly closing the door to the senator joining his potential White House administration.

The former vice president celebrated Ms Warren in a statement posted to his Twitter account shortly after she announced her decision to end a bid for the Democratic nomination on Thursday, writing: “Her work in Washington, in Massachusetts, and on the campaign trail has made a real difference in people’s lives.”

“We needed her voice in this race,” he said, “and we need her continued work in the Senate.”

Mr Biden’s statement on the latest departure from the 2020 race left virtually no room for political analysts and TV pundits to ponder whether he would announce Ms Warren as his running mate, if he managed to secure the Democratic nomination.

His comments came as the Massachusetts senator told her supporters on Thursday she needed “some space” to decide how to move forward after suffering a weak showing in the first key votes across the country, as well as on Super Tuesday. While Ms Warren was at one point seen as a possible frontrunner in the Democratic primaries, her support slipped in recent months as Bernie Sanders — another progressive candidate in the race — gained momentum against Mr Biden following the Iowa caucus and New Hampshire primaries.

“I want to take a little time to think a little more”, Ms Warren said on Thursday, as reports indicated she was looking for a way to exit the campaign gracefully.

While progressives called on her to back Mr Sanders for the nomination, the Vermont senator also released a statement that said Ms Warren “has taken on the most powerful corporate interests because she cares about those who have been left behind.”

“Without her, the progressive movement would not be nearly as strong as it is today,” he added. “I know that she'll stay in this fight and we are grateful that she will.”

Ms Warren, who declined to endorse Bernie Sanders for the presidency in 2016 and instead backed former Democratic nominee Hillary Clinton, could be seen as a crucial voice of support for either Mr Sanders or Mr Biden as the two appeared set for a lengthy and challenging competition.

It remains unclear for now whether Ms Warren will back either of the leading Democratic candidates. Several former presidential hopefuls have backed out of the race in recent weeks, from Mike Bloomberg to Pete Buttigieg and Amy Klobuchar, with all three of those moderate candidates swiftly endorsing Mr Biden for the nomination.