Addressing the coronavirus pandemic, confronting the climate crisis and building public trust in science and technology will be among the Biden administration's key areas of focus, the president-elect said during a press briefing introducing four key members of his science team.

Building back the economy "to ensure prosperity is fully shared all across America" and ensuring the U.S. "leads the world in technologies and industries that the future" will also be a focus, Biden said Saturday during an address in Wilmington, Delaware.

Helping lead those initiatives will be Eric Lander, the presidential science advisor-designate, a position that for the first time will be a cabinet rank, Biden noted.

"I've always said that the Biden-Harris administration will lead with science and truth," Biden said. "We believe in both. This is how we're going to, God willing, overcome the pandemic and build our country back better than it was before. That's why for the first time in history, I'm going to be elevating the presidential science advisor to a Cabinet rank, because we think it's that important."

Frances Arnold and Maria Zuber will be at the helm of the first all-women team to lead the President’s Council of Advisors on Science and Technology.

Alondra Nelson will also be deputy director for science and society for the Office of Science and Technology Policy.

Dr. Francis Collins, who was not present at the event, will also continue in his role as director of the National Institutes of Health.Biden thanked him for "being willing to stay on," saying that it wasn't his original plan.

"I've known Dr. Collins for many years. I worked with him closely," Biden said, accling him "brilliant, a pioneer, a true leader."

"This is the most exciting announcement that I have gotten to make in the entire Cabinet," Biden said of his picks. "These are among the brightest, most dedicated people, not only in the country but the world."

MyPillow CEO Mike Lindell on Friday was pictured outside of the Oval Office with a document appearing to detail drastic actions just days away from Biden's inauguration. The pillow inventor, who previously called for “martial law” in a now-deleted tweet, confirmed to ABC News that he met with Trump and presented him with a separate document filled with theories regarding election hacking.

The theories are related to repeatedly discredited claims that Trump had actually won the election.

The photograph went viral on Twitter after users speculated the document showed mentions of “martial law” and the “insurrection act.” 

White House sources stressed that nothing Lindell presented was taken seriously nor would it be acted upon by administration officials.

In an interview with ABC News, Lindell, a fierce supporter of the president, said his meeting with Trump was brief ("it was real fast") and said White House lawyers who reviewed the documents after his meeting with the president seemed “disengaged” and “disinterested,” which he said was “disturbing.”

“There was no mention of martial law,” Lindell said regarding the document photographed by the Washington Post, which he claims comes from one of the attorneys he said he has hired to investigate election fraud but would not identify to ABC News. 

Another section of the notes appears to read, "Move Kash Patel to CIA Acting" and "Make clear this is China/Iran." Much of the notes are not visible in the photo.

When asked if he read that document, Lindell told ABC News, “I glanced at it.”

“I'm going to be honest. I read that -- I don't know the names. I don't understand half the stuff on there," Lindell said. "...I don't know the names on there. I think there were suggestions on who to move."

Lindell said the photographed document was just a part of the bigger packet he had brought to the White House, and that his main intention was to show the president an article that alleges multiple foreign countries hacked the 2020 U.S. election. He said during the brief time he had with the president, he spoke to him about this article.

-ABC News’ Will Steakin, Soorin Kim and John Santucci

Biden and Vice President-elect Kamala Harris will introduce key picks for their science team in Wilmington, Delaware, Saturday afternoon.

The picks are:

-Eric Lander: Nominee for director of the Office of Science and Technology Policy (OSTP) and presidential science advisor-designate.

-Alondra Nelson: OSTP deputy director for science and society

-Frances H. Arnold: Co-chair of the President’s Council of Advisors on Science and Technology (PCAST)

-Maria Zuber: Co-chair of the President’s Council of Advisors on Science and Technology (PCAST)

In a press release, the Biden transition team said the picks will help the Biden-Harris administration "confront some of the biggest crises and challenges of our time, from climate change and the impact of technology on society to pandemics, racial inequity, and the current historic economic downturn."

Biden has announced a new slate of nominations and staff at the Department of State. Many of the picks have ties to both Biden and former President Barack Obama.

The picks are:

-Wendy R. Sherman: Deputy secretary of state

-Brian P. McKeon: Deputy secretary for management and resources

-Bonnie Jenkins: Under secretary for arms control and international security affairs

-Victoria Nuland: Under secretary for political affairs

-Uzra Zeya: Under secretary for civilian security, democracy, and human rights

In a statement, the Biden transition team said these key nominations will help "build back better at the State Department, renew and reimagine American leadership to keep us safe at home and abroad, and address the defining challenges of our time — from infectious disease, to terrorism, China, nuclear proliferation, cyber threats, and climate change. They will put into practice the President-elect and Secretary-designate’s vision of a foreign policy that promotes America’s security, prosperity, and values, and delivers for the middle class."

-ABC News' Beatrice Peterson

Vice President-elect Kamala Harris kicked off the first night of inaugural events with closing remarks on Saturday during an event titled "America United: An Inauguration Welcome Event Celebrating America’s Changemakers."

Harris noted the work that supporters did to make this moment what it is despite challenges due to coronavirus.

"I'm so excited to officially welcome you to the 59th presidential inauguration," Harris said. "We are here not only to celebrate and mark the start of a new administration, but to honor the work you have done from the primaries to the general election, right up to this very moment -- from Zoom grassroots fundraisers to union meetings on Google Meet to our drive-in rallies -- you were there every step of the way. And on the eve of this inauguration, the president-elect and I thank you for all you have done for our country; we would not be here without you."

Harris shared a message to young Americans to keep fighting and to dream with ambition. She noted that fighting for working people, rooting out systemic racism and combating the climate crisis, while strengthening democracy, are key goals for the administration.

"And I also would not be here without the generations of Americans who struggled and sacrificed to open up opportunity in our country. I stand on their shoulders. And as I've said before, while I may be the first woman to serve as vice president, I will not be the last," she said.

-ABC News' Beatrice Peterson