Updated

President Biden has tested positive for COVID-19, the White House said on Thursday. 

"This morning, President Biden tested positive for COVID-19," White House Press Secretary Karine Jean-Pierre said in a written statement. "He is fully vaccinated and twice boosted and experiencing very mild symptoms.  He has begun taking Paxlovid. Consistent with CDC guidelines, he will isolate at the White House and will continue to carry out all of his duties fully during that time.  He has been in contact with members of the White House staff by phone this morning, and will participate in his planned meetings at the White House this morning via phone and Zoom from the residence.

"Consistent with White House protocol for positive COVID cases, which goes above and beyond CDC guidance, he will continue to work in isolation until he tests negative," Jean-Pierre continued. "Once he tests negative, he will return to in-person work.

BIDEN ANNOUNCES EXECUTIVE ACTIONS ON 'CLIMATE CRISIS;' FOCUSES ON EXTREME HEAT AND BOOSTING OFFSHORE WIND

"Out of an abundance of transparency, the White House will provide a daily update on the President’s status as he continues to carry out the full duties of the office while in isolation," she said.

Biden speaks with media

President Biden speaks to media after exiting Air Force One at Andrews Air Force Base in Maryland on Wednesday, July 20, 2022.  (AP Photo/Evan Vucci)

The official Twitter account for President Biden later tweeted a photo of him sitting at his desk with a pen in hand overlooking some papers. 

"Folks, I'm doing great. Thanks for your concern," the message from the president said. "Just called Senator Casey, Congressman Cartwright, and Mayor Cognetti (and my Scranton cousins!) to send my regrets for missing our event today. Keeping busy!"

President Biden in the White House after positive COVID-19 test

President Biden released a photo of himself in the White House after testing positive for COVID-19 on Thursday, July 21, 2022. (White House)

Per standard protocol for any positive case at the White House, the White House Medical Unit will inform all close contacts of the president during the day Thursday, including any members of Congress and any members of the press who interacted with Biden during his travel Wednesday, the earlier White House statement added.

President Biden traveled to Somerset, Mass., on Wednesday, July 20, 2022, to deliver remarks on tackling the climate crisis and seizing the opportunity of a clean energy future to create jobs and lower costs for families. (David L. Ryan/The Boston Globe via Getty Images)

Biden's last previous test for COVID was Tuesday, when he had a negative test result, the White House said. 

First lady Jill Biden told reporters in Michigan that she tested negative for COVID-19 and will be keeping her schedule Thursday in accordance with CDC guidelines. 

President Biden traveled Wednesday to Somerset, Massachusetts, where he delivered a speech on the "climate crisis." He pledged $2.3 billion — the largest climate investment ever — to come from the Federal Emergency Management Agency (FEMA) for local communities to invest in infrastructure designed to address a range of disasters including extreme heat, drought, flooding, hurricanes and tornadoes.

kerry, markey and warren at biden climate speech in massachusetts

From left to right, U.S. special presidential envoy for climate John Kerry, Sen. Ed Markey and Sen. Elizabeth Warren applaud during President Biden's speech about the climate in Somerset, Mass., on Wednesday, July 20, 2022.  (David L. Ryan/The Boston Globe via Getty Images)

"Climate change is literally an existential threat to our nation and to the world," Biden said Wednesday during his speech. "So, my message today is this: Since Congress is not acting as it should — and these guys here are, but we’re not getting many Republican votes — this is an emergency.  An emergency.  And I will — I will look at it that way." 

Biden was mocked on Twitter for either an apparent bombshell or an egregious gaffe during the speech Wednesday suggesting that he has cancer — possibly linked to him growing up in an area of Delaware rampant with oil pollution. 

But the remark prompted the White House to quickly clarify that Biden was referring to past the removal of non-melanoma skin cancers before he became president. 

Among those who traveled with Biden on Air Force One to Massachusetts were Massachusetts Democrats Sen. Ed Markey, Sen. Elizabeth Warren, Rep. Jake Auchincloss and Rep. Bill Keating. 

U.S. special presidential envoy for climate John Kerry, Markey and Warren were photographed applauding in folding chairs while listening to Biden's outdoor speech. Meanwhile, Auchincloss tweeted photos of himself shaking hands with Biden and posing for pictures while in close proximity to the president on Air Force One on Wednesday. 

"Senator Markey is testing this morning, as he does regularly, and will remain masked and socially distanced per public health guidelines," a spokesperson for Markey said Thursday in a statement to Fox News. "Senator Markey is double vaccinated and double boosted."

White House Press Secretary Karine Jean-Pierre was also on Air Force One with the president Wednesday. 

She will still hold a press briefing with the White House Press Pool on Thursday afternoon, joined by COVID-19 Response Coordinator Dr. Ashish Jha.

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Other Biden administration officials on the plane with the president Wednesday were Bruce Reed, Assistant to the President and Deputy Chief of Staff; Annie Tomasini, Assistant to the President and Director of Oval Office Operations; Gina McCarthy, Assistant to the President and National Climate Advisor; Vinay Reddy, Deputy Assistant to the President and Director of Speechwriting; Stephen Goepfert, Special Assistant to the President and Personal Aide to the President; Curtis Reid, Special Assistant to the President and Senior Director for Multilateral Affairs; and Travis Dredd, Special Assistant to the President and Trip Director. 

This is a developing story. Check back for updates.