In keeping with the White House's focus of the day, Biden held a bipartisan Oval Office meeting Wednesday with House and Senate members ahead of signing an executive order mandating a review of critical U.S. supply chains.

"The last year has shown the vulnerability we have with some of the supply chains, including the PPE that we needed badly but had to go abroad to get. And there are current strategies," Biden said.

Biden praised the bipartisan effort to address the shortage of the chips for cars and said the group planned to discuss the problem, along with other shortage issues.

-ABC News' Molly Nagle

The White House was surprised to discover that Johnson & Johnson will only have about 3 to 4 million doses of its vaccine ready to ship once the FDA grants an emergency use authorization, White House press secretary Jen Psaki said during a press briefing Wednesday.

Johnson & Johnson had estimated it could ship 12 million doses at the end of February in a $1 billion contract signed with the federal government in August.

“We were surprised to learn that Johnson & Johnson was behind on their manufacturing. As you noted, it was kind of reported earlier to be about 10 million, and now it's more like 3 to 4 million doses that they would be ready to ship next week if they are moved through the FDA process, which is not yet concluded, just to note," Psaki said. "And we are going to continue to work with them on ensuring that that can be expedited.”

Despite the initial availability, Johnson & Johnson has said it expects 20 million doses to be available by the end of March and to meet its contractual obligation for 100 million doses by the end of June.

-ABC News' Sarah Kolinovsky

Veteran diplomat Linda Thomas-Greenfield was sworn in Wednesday morning as Biden's U.N. ambassador. Thomas-Greenfield, known for her "gumbo diplomacy", is a Louisiana native and child of the segregated South.

After being sworn in, Thomas-Greenfield tweeted saying she was "honored" to hold the post.

"Diplomacy is back. Multilateralism is back," Thomas-Greenfield said in the tweet. "America is back."

White House press secretary Jen Psaki was asked during a press briefing Wednesday whether the postponement of Senate hearings for Biden's pick to manage the Office of Management and Budget was a setback and Psaki said she wouldn't "put it in those terms."

Psaki emphasized that the administration is still "fighting" for Tanden's nomination and remains committed to getting Biden's pick confirmed. When asked whether Tanden had offered to withdraw her nomination, Psaki said that is "not the stage" the administration is in.

"The stage we’re in is working to continue to fight for her nomination. And, as you know, it’s a numbers game, right? It's a matter of getting one Republican to support her nomination," Psaki said. "We're continuing to do that outreach, answer questions they have, and continue to reiterate her qualifications."

Biden’s nominee for secretary of the interior, Rep. Deb Haaland, D-Ariz., appeared before the Senate Energy and Natural Resources Committee for the first round of questioning in her confirmation hearing Tuesday.

Haaland introduced herself in the native language of the Laguna Pueblo and thanked her family, her partner and her ancestors. She also acknowledged that the hearing was taking place on the native lands of the Anacostia, Piscataway and Nakochtank tribes.

She said her priorities would be valuing career employees at the Department of the Interior and promoting clean energy. For Native American communities, she said she would focus on bringing broadband access to them and addressing the high number of missing and murdered Native American women. She also talked about her support for a modern Civilian Conservation Corps as a way of offsetting potential job loss from a transition to cleaner energy.

“But we must also recognize that the energy industry is innovating, and our climate challenge must be addressed," she said in her opening statement. "Together we can work to position our nation and all of its people for success in the future, and I am committed to working cooperatively with all stakeholders, and all of Congress, to strike the right balance going forward.”

Throughout the hearing, when questioned about her past statements and positions, Haaland said that if confirmed she would be advancing Biden’s interests. She dodged a question about her stance on fracking, saying the president does not support a fracking ban.

In his opening statement, Sen. John Barrasso, R-Wyo., said he was troubled by Haaland’s “radical” views, a sentiment also expressed by other Republicans on the committee. He said he would oppose Haaland’s nomination. During his questioning, Barrasso pressed Haaland on an October tweet that said Republicans don’t believe in science.

The committee will be back Wednesday at 10 a.m. for the second round of questioning.

-ABC News' Adia Robinson