The White House continues to back Neera Tanden, Biden's pick to oversee the Office of Management and Budget, despite criticism from Republicans about her tweets that have been critical of conservatives.

White House press secretary Jen Psaki was asked during a press briefing Tuesday if there were other people in consideration for the position, and she said there is only "one candidate" and that is Tanden.

"She has had 44 meetings now with senators of both parties, she's spoken with 15 senators from both parties since Friday," Psaki said. "Some of those were repeats of people she had spoken with previously but, as I noted yesterday, she's committed to rolling up her sleeves, having those conversations, answering questions as they come up, reiterating her commitment to working with people across the aisle."

The Senate has confirmed Linda Thomas-Greenfield, a retired career ambassador and former top U.S. diplomat for Africa, as ambassador to the United Nations. The final vote was 78-20, with top Republicans, like Senate Minority Leader Mitch McConnell, voting in favor.

Thomas-Greenfield is the eighth official and the first Black woman confirmed to Biden's Cabinet. The U.S. will assume the presidency of the U.N. Security Council on Monday for the month of March, and Thomas-Greenfield will now be in place for that term, as the U.S. sets the agenda for the U.N.'s highest body.

Her nomination had been held up by Sen. Ted Cruz, R-Texas, who accused Thomas-Greenfield of "moving towards and embracing the Chinese Communist Party" because of a speech she gave at a historically Black college in Georgia that was co-hosted by its Confucius Institute, a Chinese government-funded program that promotes the CCP as part of a language and cultural curriculum. However, Thomas-Greenfield said she regrets accepting the invitation and would not do it again, adding she was "appalled" by the Confucius Institute's treatment of poor Black Georgians.

-ABC News' Conor Finnegan

Biden and first lady Jill Biden will travel to Houston, Texas, on Friday, the White House announced.

The president will visit the state in the aftermath of the catastrophic winter storm that left millions of Texas residents without power and water and killed at least 30 people in the state.

White House press secretary Jen Psaki said last week that the president was considering a trip but was cognizant of the burden and additional resources that a presidential visit can bring.

Biden has already approved a major disaster declaration for the state, opening up federal funds to 77 of the state's 254 counties.

-ABC News' Justin Gomez

On the second day of Judge Merrick Garland's confirmation hearing, the nominee will not testify but five witnesses will testify virtually about his nomination and credentials. Those witnesses include Wade Henderson, CEO of the Leadership Conference on Civil and Human Rights, Josh Blackman, South College Texas of law professor, Andrea Tucker, a mother in D.C., whose twin children Garland tutors, Ken Starr, former solicitor general and U.S. circuit judge, and Donna Bucella, former director for Executive Office of U.S. attorneys.

Garland emerged virtually unscathed after Monday's hearing, earning praise from senators on both sides of the aisle as he fielded questions on domestic terrorism, racial justice issues and restoring independence to the Justice Department, among other topics.

Republican Sens. Ted Cruz, R-Texas, and Tom Cotton, R-Ark., did express concern over what they described as Garland's unwillingness to pledge that he will not fire special counsel John Durham without proper cause, a commitment they note former attorney general William Barr made during his confirmation hearing about then-special counsel Robert Mueller.

Garland repeatedly emphasized that because he had no knowledge of Durham's investigation he wanted to meet with him first before making a decision but said that because Durham hasn't yet been fired in the new administration he sees no reason to doubt that decision.

Other Republicans, like Sen. Josh Hawley, R-Mo., appeared to grow frustrated over Garland's unwillingness to engage on questions about his views on immigration policy. Garland said he was not completely aware of Biden's immigration policy proposals so declined to wade into the issue.

-ABC News' Alexander Mallin

Biden's pick for director of the Office of Management and Budget, Neera Tanden, was supposed to testify before the Senate Budget Committee Wednesday morning, however the committee postponed Tanden's confirmation hearing, according to two sources with knowledge of the matter.

In addition, a vote on the nomination in the Senate Homeland Security Committee has also been postponed, a spokesperson told ABC News that the delay was because, "members need more time to consider the nominee."

Moments after news broke that two Senate committees postponed their votes on Tanden's nomination, White House press secretary Jen Psaki defended Tanden in a Twitter thread, making clear the White House is standing by their nominee.

"Neera Tanden is a leading policy expert who brings critical qualifications to the table during this time of unprecedented crisis. She also has important perspective and values, understanding firsthand the powerful difference policy can make in the lives of those going through hard times," Psaki tweeted.

The nomination has been in trouble since lawmakers became critical of Tanden’s combative tweets aimed at Republicans and her effort to delete them before her nomination. Her nomination was in danger of being derailed when moderate Democratic Sen. Joe Manchin, D-W.Va., announced his opposition to her nomination, citing her temperament.

-ABC News' Trish Turner, Molly Nagle, Katherine Faulders and Sarah Kolinovsky