Biden signed an executive order Wednesday that will begin a 100-day investigation into vulnerabilities in the supply chain of critical sectors including computer chips, large capacity batteries, active pharmaceutical ingredients and critical and strategic materials, including rare earth minerals.

Biden touted the move as something that will strengthen America for future challenges like the COVID-19 pandemic, which revealed myriad flaws in the supply chain.

"This is about making sure the United States can meet every challenge we face in this new era," Biden said. "Pandemics, but also in defense, cybersecurity, climate change, and so much more. And the best way to do that is by protecting and sharpening America’s competitive edge by investing here at home."

In remarks before the signing, he called the subject one of few "where Republicans and Democrats agreed," having met earlier in the day with a bipartisan group of lawmakers.

Sen. Richard Shelby, R-Ala., a top Republican on the Appropriations Committee, is throwing his weight behind an alternative nominee to head the Office of Management and Budget: Shalanda Young.

Young was nominated by Biden to be deputy director of the Office of Management and Budget. Young was most recently the staff director at House Appropriations, and she and Shelby have a close working relationship.

“I believe she would be good in that role. She’s smart, she knows the process inside-out, and she’s an honest broker who has demonstrated the ability to work with both sides and get things done. She would have my support, and I suspect many of my Republican colleagues would support her, as well," Shelby said in a statement. "But that’s up to the Biden Administration.”

White House press secretary Jen Psaki was asked about Shelby's support on Wednesday and the possibility of Young being a Neera Tanden replacement, but she made clear that the White House maintains support for Tanden.

-ABC News' Trish Turner

Energy and Natural Resources Committee Chairman Sen. Joe Manchin, D-W.V., will vote to confirm Rep. Deb Haaland's, D-Ariz., nomination to serve as secretary of the interior, easing concerns that Haaland's appointment could be in jeopardy.

Manchin has been in close focus on this and other nominations this week, as the moderate Democrat has significant ability to jeopardize nominees in the evenly divided Senate.

Manchin has said he will oppose the nomination of Neera Tanden to the Office of Management and Budget and has not committed to a position on Xavier Becerra's nomination to lead the Department of Health and Human Services.

"I believe that every Presidential nominee and every Member of Congress must be committed to a new era of bipartisanship. That is the standard the overwhelming majority of Americans expect and deserve," Manchin said in a statement. "With respect to Representative Haaland and her confirmation hearing, while we do not agree on every issue, she reaffirmed her strong commitment to bipartisanship, addressing the diverse needs of our country and maintaining our nation’s energy independence."

-ABC News' Allison Pecorin

Biden has officially extended the national emergency declared over the COVID-19 pandemic beyond March 1. By law, the national emergency would have ended a year after it was declared unless the president took action within 90 days of the expiration date.

"The COVID-19 pandemic continues to cause significant risk to the public health and safety of the Nation," Biden wrote in his letter to Congress. "More than 500,000 people in this Nation have perished from the disease, and it is essential to continue to combat and respond to COVID-19 with the full capacity and capability of the Federal Government."

The national emergency was initially ordered by former President Donald Trump on March 13, 2020, freeing up financial resources for the country as the pandemic took hold.

-ABC News' Molly Nagle

Following his brief speech, Biden, first lady Jill Biden, Vice President Kamala Harris and second gentleman Doug Emhoff walked out to the South Portico at the White House where candles were lit and displayed on the steps for the moment of silence.

Earlier, the National Cathedral rang its bells to honor the more than 500,000 Americans who died from the coronavirus.

"I received a letter from a daughter whose father died of COVID-19 on Easter Sunday last year," Biden said before the ceremony. "She and her children, his grandchildren, enter Lent this season, a season of reflection and renewal, with heavy hearts. Unable to properly mourn, she asked me in the letter, what was our loss among so many others? Well, that's what has been so cruel."

"So many of the rituals that help us cope, that help us honor those we loved, haven't been available to us. The final rites, with family gathered around, the proper home going, showered with stories and love, tribal leaders passing out the final traditions of sacred cultures on sacred lands," he continued. "As a nation, we cannot and we must not let this go on. That's why the day before my inauguration ... I said, 'to heal -- to heal, we must remember.' I know it's hard. I promise you, I know it's hard. I remember. But that's how you heal. You have to remember."