Joe Biden's campaign on Thursday morning announced four co-chairs who will lead a committee to select his running mate, formalizing a process that will be one of the most critical decisions of his campaign.

The committee will be led by a range of officials who have been close to Biden at various points during his career, including former senator Chris Dodd, D-Conn., Rep. Lisa Blunt Rochester, D-Del., Los Angeles Mayor Eric Garcetti and former White House counsel Cynthia Hogan.

"Selecting a vice-presidential candidate is one of the most important decisions in a presidential campaign and no one knows this more than Joe Biden," said campaign manager Jen O'Malley Dillon. "These four co-chairs reflect the strength and diversity of our party, and will provide tremendous insight and expertise to what will be a rigorous selection and vetting process."

Biden has pledged to select a woman as his running mate, and attention has focused on fewer than a dozen potential candidates.

Part of the process will focus on vetting potential candidates, which could involve digging through public records, news accounts, as well as tax returns.

The vetting team will be led by former White House counsel Bob Bauer, campaign general counsel Dana Remus and former White House homeland security adviser Lisa Monaco.

During a fund-raiser on Wednesday, Biden said that the vetting would take several months — “God-willing, we will have that vetting done by July” — and he reiterated one of his most important qualifications.

"I need someone who's going to be, as [former president] Barack [Obama] said, 'Simpatico with me,' who is a real partner in progress and is ready to be president on a moment's notice," Biden said. "There are a lot of women out there with the experience to do that job."

Biden said he has been thinking about his potential Cabinet members, saying he hoped it would be a bipartisan group and adding that he may announce some of them during the campaign.

“I think about maybe announcing, not the whole Cabinet, but some . . . so people will have a better idea of what my administration will look like,” he said. “But I promise you, it’s going to look like the country.”