After an expanded detention facility for child migrants reopened in Carrizo Springs, Texas, Rep. Alexandria Ocasio-Cortez, D-N.Y., tweeted Tuesday, “This is not okay, never has been okay, never will be okay - no matter the administration or party.”

In a press briefing Wednesday, Psaki attempted to cast the Biden administration’s efforts to manage immigration as a major improvement over President Donald Trump’s policies but didn’t fully address Ocasio-Cortez's criticism that such facilities shouldn’t exist at all.

Psaki said the administration had three options when it comes to child migrants: to send them back to their countries (which she said can be dangerous), to transfer them to a facility managed by the Department of Health and Human Services, or to put them in the care of families or sponsors "without any vetting." She said the administration has chosen the middle option.

“What we are doing is working as quickly as possible to process these kids into these HHS facilities, which have been revamped, which have medical and educational services available, so that we can then transfer them to families. That's what our approach is,” Psaki said.

Psaki would not commit to a request to allow media in to prove that children are treated humanely, citing privacy and security concerns. Psaki tried to explain the administration’s options in dealing with minors at the border and why the detention facilities have become a primary strategy.

“This is a difficult situation. It's a difficult choice. That's the choice we've made,” she said.

Psaki also attempted to defend delays in transferring children from facilities run by Customs and Border Protection, which often lack amenities, to Health and Human Service facilities that are intended for longer-term care. By law, children are supposed to spend no more than 72 hours in Customs and Border Protection facilities after initial apprehension.

“There were some delays last week because of weather, and because some of these facilities to safely move these kids to, did not have power and were not in a place where they could -- they had the capacity to take in these kids and do it safely. That is not our objective. That is not our goal," Psaki said. "So some, unfortunately, did stay four days, five days, or longer, but the objective is to move them as quickly as possible to the HHS sponsored facilities.”

-ABC News' Sarah Kolinovsky

In keeping with the White House's focus of the day, Biden held a bipartisan Oval Office meeting Wednesday with House and Senate members ahead of signing an executive order mandating a review of critical U.S. supply chains.

"The last year has shown the vulnerability we have with some of the supply chains, including the PPE that we needed badly but had to go abroad to get. And there are current strategies," Biden said.

Biden praised the bipartisan effort to address the shortage of the chips for cars and said the group planned to discuss the problem, along with other shortage issues.

-ABC News' Molly Nagle

The White House was surprised to discover that Johnson & Johnson will only have about 3 to 4 million doses of its vaccine ready to ship once the FDA grants an emergency use authorization, White House press secretary Jen Psaki said during a press briefing Wednesday.

Johnson & Johnson had estimated it could ship 12 million doses at the end of February in a $1 billion contract signed with the federal government in August.

“We were surprised to learn that Johnson & Johnson was behind on their manufacturing. As you noted, it was kind of reported earlier to be about 10 million, and now it's more like 3 to 4 million doses that they would be ready to ship next week if they are moved through the FDA process, which is not yet concluded, just to note," Psaki said. "And we are going to continue to work with them on ensuring that that can be expedited.”

Despite the initial availability, Johnson & Johnson has said it expects 20 million doses to be available by the end of March and to meet its contractual obligation for 100 million doses by the end of June.

-ABC News' Sarah Kolinovsky

Veteran diplomat Linda Thomas-Greenfield was sworn in Wednesday morning as Biden's U.N. ambassador. Thomas-Greenfield, known for her "gumbo diplomacy", is a Louisiana native and child of the segregated South.

After being sworn in, Thomas-Greenfield tweeted saying she was "honored" to hold the post.

"Diplomacy is back. Multilateralism is back," Thomas-Greenfield said in the tweet. "America is back."

After the U.S. conducted a military airstrike in eastern Syria along the border with Iraq on Thursday, White House press secretary Jen Psaki defended the president's authority to carry out the strike amid bipartisan pushback from members of Congress.

"As a matter of domestic law, the president took this action, pursuant to his Article II authority to defend U.S. personnel. The targets were chosen to correspond to the recent attacks on facilities, and to deter the risk of additional attacks over the coming weeks," Psaki said. "As a matter of international law, the United States acted pursuant to its right of self-defense, as reflected in Article 51 of the U.N. charter."

Psaki said the move was "necessary" and "proportionate" and reflected the president's unambiguous commitment to protecting American lives.

The Department of Defense briefed congressional leadership before the action Thursday night, according to a spokesperson on the National Security Council. The administration has been briefing lawmakers at the member and staff level Friday. There will be a full classified briefing early next week, and sooner if Congress wants, according to the spokesperson.

-ABC News' Molly Nagle