The U.S. Food and Drug Administration authorized use of a third COVID-19 vaccine in the U.S., declaring the Johnson & Johnson vaccine safe and effective in adults 18 and older.

ABC News Chief Anchor George Stephanopoulos asked Dr. Anthony Fauci about hesitancy from people over its reported efficacy compared to others.

"What do you say to those who want to wait for Moderna and Pfizr?" Stephanopoulos asked.

"We have to get away from that line of thought," Fauci responded. "We have three highly efficacious vaccines. Safe and efficacious."

"If I went into a clinic and said we have JJ now, I would take the one that is available to me now," Fauci continued.

The White House released a letter Saturday from President Biden to the speaker of the House and president pro tempore of the Senate on the airstrike in eastern Syria, in his effort to keep Congress "fully informed, consistent with the War Powers Act."

"I directed this military action consistent with my responsibility to protect United States citizens both at home and abroad and in furtherance of United States national security and foreign policy interests, pursuant to my constitutional authority to conduct United States foreign relations and as Commander in Chief and Chief Executive. The United States took this action pursuant to the United States' inherent right of self-defense as reflected in Article 51 of the United Nations Charter," Biden wrote in the letter.

This comes following some bipartisan criticism the White House received over the decision to carry out the airstrike in Syria.

-ABC News' Molly Nagle

As Biden departed the White House to board Marine One Saturday afternoon, he was asked if he planned to punish Saudi Arabia’s crown prince following a U.S. intelligence report that concluded he ordered the killing of journalist Jamal Khashoggi.

Biden carefully teased an announcement but said it wouldn’t specifically pertain to Khashoggi’s murder.

He said, “there will be an announcement on Monday as to what we’re going to be doing with Saudi Arabia in general.”

The president then left the White House for Delaware.

On Friday the Office of Director of National Intelligence released a highly anticipated report on the death of Khashoggi, a Washington Post columnist and Saudi dissident who was murdered and dismembered at the Saudi consulate in Istanbul in Oct. 2018.

It revealed the U.S. intelligence community found Saudi Arabia’s Crown Prince Muhammad bin Salman approved an operation to capture or kill him.

The Saudi government has denied that that the crown prince was involved and instead blamed the death on a rogue team of government agents.

The killing has roiled the United States' longstanding ties with Saudi Arabia.

Biden said he spoke to King Salman on Thursday, one day before the report was released.

In honor of Black History Month, NASA astronaut Victor Glover welcomed Harris to the International Space Station via virtual chat.

A pre-recorded video shared on Saturday by NASA, shows Harris and Glover discussing several topics, including the legacy of human spaceflight, observing Earth from the space station and prepping for missions from the Moon to Mars.

Glover is a long-duration crew member on the International Space Station and is responsible for spacecraft systems and performance.

Biden's pick for attorney general, Merrick Garland, was questioned by Sen. Mike Lee, R-Utah, about his views on the Second Amendment right to bear arms. Garland cited Supreme Court precedent saying the right to bear arms in his belief is one that is "subject to some limitations," citing former Supreme Court Justice Antonin Scalia. He wouldn't answer directly whether he supports "universal background checks" for all firearms owners but said that he believed it is important for checks to ensure that people like felons or other potentially dangerous individuals are not permitted to buy guns.

Sen. Ted Cruz, R-Texas, used his line of questioning to raise concerns about the Justice Department being "politicized and weaponized" under the Obama Administration and cited former Attorney General Eric Holder's comments that he saw himself as a "wingman" to former President Barack Obama. Asked whether Garland viewed himself as a "wingman" to Biden, Garland said he didn't want to comment on any of his predecessors but said he "could assure you that I do not regard myself as anything other than a lawyer for the people of the United States."

When asked about the federal death penalty, Garland said the death penalty gives him "great pause" because of the racial disparity and number of exonerations that come from death penalty cases.

"I have had a great pause about the death penalty. I am very concerned about the large number of exonerations that have occurred through DNA evidence and otherwise, not only in death penalty convictions, but also in other convictions, I think, a terrible thing occurs when somebody is convicted of a crime that they did not commit," Garland said.

-ABC News' Luke Barr