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

When he leaves for Alamo, Texas, Tuesday morning, it will be President Trump's first time in public since last Wednesday -- the day his supporters stormed the U.S. Capitol after he encouraged a crowd of thousands, at a rally beforehand, to put pressure on lawmakers affirming Biden's victory in Congress.

Apart from posting video on Twitter last Thursday, before the platform permanently suspended his account, the president has remained behind closed doors at the White House -- spending his final days in office out of the public eye -- but is expected to break his silence with afternoon remarks.

"President Trump is expected to travel to Alamo, Texas, on Tuesday to mark the completion of more than 400 miles of border wall -- a promise made, promise kept -- and his administration's efforts to reform our broken immigration system," White House deputy press secretary Judd Deere told reporters ahead of the visit.

The president is facing renewed calls from congressional Democrats to be removed from office in the wake of last week's riot, with the House poised to pass an impeachment resolution as early as Wednesday charging the president with incitement of insurrection -- and setting Trump up to be the first president in history to be impeached twice.

Trump, for the first time since the assault, spoke with Vice President Mike Pence at the urging of his advisers and allies in an Oval Office meeting Monday that lasted 90 minutes and was friendly in nature, according to White House officials briefed on the meeting. Pence is not expected to invoke the 25th Amendment as House Speaker Nancy Pelosi has called on him to do.

Biden, on Tuesday, will receive the President’s Daily Brief and meet with advisers, while his transition team and allies in Congress begin a push to confirm his national security nominees so they're in place next week, with priority on the confirmation of Department of Homeland Security Secretary-designate Alejandro Mayorkas.

Defense Secretary-designate Gen. Lloyd Austin, nominee for Director of National Intelligence Avril Haines and Secretary of State-designate Tony Blinken will also be part of the push ahead of their hearings on Capitol Hill.

Biden’s nominees may also need now to contend with an impeachment trial in the Senate. Biden suggested in remarks Monday the Senate look into splitting the its time in order to confirm his nominees, pass COVID-19 relief and deal with a presidential impeachment.

-ABC News' John Parkinson, Ben Gittleson and Molly Nagle