President Biden said Wednesday that the current shortage of coronavirus tests is not a failure of his administration but expressed regret that he did not ramp up supplies sooner ahead of the rapid spread of the omicron variant.

"I don't think it's a failure," Biden said in an interview with ABC’s David Muir that aired Wednesday evening. "You could argue that we should have known a year ago, six months ago, two months ago, a month ago."

"I wish I had thought about ordering half a billion [tests] two months ago," Biden added.

Biden announced Tuesday that his administration would purchase 500 million at-home COVID-19 tests to give to any American who wants one free of charge. 

The administration is building a website to help distribute the tests and expects to begin delivering them next month, though questions such as the delivery mechanism and how many tests each family can order have yet to be answered.

The testing kits are in addition to the 50 million that the administration has purchased and distributed to community health centers. 

Meanwhile, communities across the country are experiencing shortages of at-home tests, and public sites are seeing long lines as Americans seek out tests before the holidays.

Cases in the U.S. are rising due to the circulation of the omicron variant, which became the dominant strain in the U.S. earlier this week.

During the interview, Biden insisted that while health experts knew that more contagious variants of COVID-19 were possible, his administration and other experts did not see omicron coming.

“Nobody saw it coming. Nobody in the whole world,” Biden said.

Asked if the current situation with tests was good enough two years into the pandemic, Biden answered, "Nothing has been good enough."

The president defended his administration’s pandemic response and said that the U.S. is in a demonstrably different position than last year, when the Centers for Disease Control and Prevention discouraged in-person gatherings for the holidays. He noted that more than 200 million Americans are fully vaccinated against COVID-19. Only about one-third of those have received booster shots.

Biden said that family members who are vaccinated can safely gather with one another for Christmas, though he recommended that individuals test themselves beforehand to ensure they are not positive for COVID-19. Biden said he and his family members would take tests before the holiday.

“This is not March of 2020. This is a very different time,” Biden said.

Biden also said that he did not overpromise when he said on July 4 that Americans were closer than ever to declaring “independence from the virus.”

“We were closer than ever, but there’s a lot we don’t know. It’s like, I’m sure you’re going to ask me, when’s this going to end? How are we going to do this? Are we sure we’re going to be able to overcome ... the virus?” Biden said, adding that the expectation is the globe will overcome COVID-19 but that “we don’t know for certain.”