Asked Wednesday night if she would accept a position as Joe Biden 's running mate if offered, the Massachusetts senator didn't hesitate, telling MSNBC's Rachel Maddow that she would. Warren was posed the question just hours after she officially endorsed Biden for the Democratic Party's nomination.

Warren earlier Wednesday tweeted out her support for the former vice president with a video message, saying, "Empathy matters. And, in this moment of crisis, it's more important than ever that the next president restores Americans' faith in good, effective government."

With her endorsement, Warren became the last of Biden's top former Democratic rivals to back him for the party's nomination.

Biden has committed to picking a woman as his running mate, and has expressed openness to choosing one of his former 2020 rivals, including Warren, Minnesota Sen. Amy Klobuchar and California Sen. Kamala Harris.

The former vice president has also mentioned former Georgia gubernatorial candidate Stacey Abrams on the campaign trail in conversations about a potential pick. Abrams has said she would be "honored" to be chosen and would make "excellent running mate." South Carolina Rep. Jim Clyburn, an influential congressman and third highest-ranking Democrat in the House of Representatives, has urged Biden to choose an African American woman.

In still other conversations about a potential vice presidential pick, Biden has mentioned New Hampshire Sen. Maggie Hassan, New Hampshire Sen. Jeanne Shaheen and former acting Attorney General Sally Yates.

Warren on Wednesday said she endorsed the former vice president because she felt it was "the right time."

"I think this is the right time. Look, I think it was important that Sen. Sanders have the time he needed and the space he needed to make the decision about what he was going to do with his campaign and now Sen. Sanders has endorsed, President Barack Obama has endorsed , and I was very, very glad to do it today," she said.

She continued: "(Biden) will fight for every human being and most of all he's a person who has empathy, and think what that means at this moment. Donald Trump measures everything and in this crisis and before, in terms of what does it mean to Donald Trump. ... Joe Biden is very different."

In announcing her endorsement earlier in the day, Warren said that "Joe Biden has spent nearly his entire life in public service. He knows that a government run with integrity, competence, and heart will save lives and save livelihoods. And we can't afford to let Donald Trump continue to endanger the lives and livelihoods of every American."