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

Late Friday, Health and Human Services Secretary Alex Azar refuted several media reports that he was resigning early, but did share his resignation letter -- effective Jan. 20 at noon -- on Twitter.

While Azar wrote on Twitter that it was his "duty to help ensure a smooth transition to President-elect Biden’s team during the pandemic" through Inauguration Day, he did criticize President Donald Trump and called on him to more strongly condemn the violence at the Capitol last week.

"Unfortunately, the actions and rhetoric following the election, especially during this past week, threaten to tarnish these and other historic legacies of this Administration," Azar wrote in the resignation letter. "The attacks on the Capitol were an assault on our democracy and on the tradition of peaceful transitions of power that the United States of America first brought to the world. I implore you to continue to condemn unequivocally any form of violence, to demand that no one attempt to disrupt the inaugural activities in Washington or elsewhere, and to continue to support unreservedly the peaceful and orderly transition of power on January 20, 2021."

Azar clarified he handed in the letter, dated Jan. 12, last week "along with every other political appointee."

The two-page letter, in which he calls serving as HHS secretary "the greatest professional privilege and honor of my life," details the administration's response to the coronavirus pandemic. Azar paints an entirely rosy picture, referring to it as a "remarkable response," despite skyrocketing deaths and case rates across most of the nation.

"While we mourn every lost life, our early, aggressive, and comprehensive efforts saved hundreds of thousands or even millions of American lives," he wrote, echoing a refrain from the president. There have been over 391,000 deaths in the U.S., nearly twice the number of the second-highest country (208,000 in Brazil).

He also highlighted the agency's efforts to combat the opioid crisis, electronic cigarettes and the HIV epidemic, and made special mention of "protect[ing] the sanctity of human life from conception to natural death."

Azar has served as HHS secretary since January 2018. President-elect Joe Biden has nominated Xavier Becerra, California's attorney general, to serve as his HHS chief.

ABC News' Ben Siu contributed to this report.