Doctors on Wednesday successfully removed two cancerous growths on the US first lady, Jill Biden, and she is now considered clear of danger, the White House physician said.

Jill Biden, accompanied by President Joe Biden, flew early morning on the presidential helicopter to Walter Reed National Medical Center in the suburbs of Washington for the outpatient procedure, known as Mohs surgery.

White House doctor Kevin O'Connor said in a memorandum that Jill Biden was experiencing post-op "facial swelling and bruising, but is in good spirits and is feeling well."

She returned to the White House later Wednesday and was "doing well and in good spirits," her spokeswoman Vanessa Valdivia said in a statement.

Doctors initially scheduled the minor surgery to remove a lesion near her right eye and to determine whether it was cancerous.

"The procedure confirmed that the small lesion was basal cell carcinoma. All cancerous tissue was successfully removed and the margins were clear of any residual skin cancer cells," O'Connor wrote.

"We will monitor the area closely as it heals, but do not anticipate any more procedures will be needed," he added.

Doctors found another lesion on the left side of Jill Biden's chest, which also turned out to be cancerous and was removed using the same procedure, he wrote.

They also found another "small lesion" on her left eyelid, which was "fully excised, with margins, and was sent for standard microscopic examination."

O'Connor noted that basal cell carcinoma lesions "do not tend to spread or metastasize, as some more serious skin cancers."

The Mohs procedure is done with local anesthetic and is considered highly effective, if done early enough, at eradicating formations of skin cancer.

"The first lady's procedure is proceeding well," White House Press Secretary Karine Jean-Pierre told reporters more than six hours after the Bidens entered the hospital.

Asked what the president was doing during the lengthy hospital visit, Jean-Pierre said, "today is about his wife. That is the focus for the president right now."

"This about the president supporting his wife of 45 years," she said.

Jill Biden, 71, is the oldest first lady in US history, while her 80-year-old husband is the oldest American president. She is believed to play an influential role inside the White House and would be a key player in a reelection bid -- something Biden has indicated he will pursue, but has yet to announce.

Cancer is a personal cause for Joe Biden, whose son Beau died in 2015 from brain cancer. He has made reducing the death rate from the disease a "presidential priority."