Psaki, 43, confirmed the news early Tuesday afternoon.
“Today, in preparation for travel to Europe, I took a PCR test this morning. That test came back positive, which means I will be adhering to CDC guidance and no longer be traveling on the President’s trip to Europe,” Psaki said in a White House statement.
Psaki said she would work from home and return to working in person at the conclusion of a five-day isolation period and a negative Covid-19 test.
Biden, who Psaki had previously said tested negative for Covid-19 on Monday, also tested negative on Tuesday via a PCR test.
“I had two socially-distanced meetings with the President yesterday, and he is not considered a close contact as defined by CDC guidance. I am sharing the news of my positive test today out of an abundance of transparency,” Psaki’s statement said.
White House principal deputy press secretary Karine Jean-Pierre will travel with Biden to Europe on Wednesday, replacing Psaki, a White House official told CNN.
White House deputy press secretary Chris Meagher stepped in to fill in for Psaki at the White House press briefing, thanking reporters for their “flexibility” with the “adjustments” as he kicked off the briefing.
Meagher said members of the press who attended Monday’s news briefing were not considered close contacts and that the White House is currently conducting contact tracing. He added that the White House is currently conducting contact tracing, but any member of the press corps who is determined to be a close contact would not have been exposed through Monday’s briefing.
Inside the White House over the last month, in accordance with federal public health guidelines, officials and visitors have not been required to wear masks or social distance. And visitors are expected to be tested for Covid-19 before attending official White House events.
Covid-19 cases in Washington have declined since their peak in early January, when the country was facing a wave of Omicron variant cases.
This story has been updated with additional developments on Tuesday.
CNN’s MJ Lee contributed to this report.