The U.S. government's new COVIDTests.gov website, set up for American households to order four free COVID-19 tests amid the omicron variant surge, is up and running ahead of its official launch on Wednesday, the White House said.

U.S. households can secure four tests at no cost when ordering from the website, with shipping expected within seven to 12 days of ordering, the White House said on Friday.

President Joe Biden has pledged to procure 1 billion free tests for Americans, and more may be ordered in the future.

His administration has come under criticism for not focusing on testing sooner. Americans waited in long lines for tests over the holidays amid a shortage.

The administration and the U.S. Postal Service have sought to avoid any major glitches in the new website like those that overshadowed the rollout of healthcare.gov, the website for President Barack Obama's Affordable Care Act.

"We can't guarantee there won't be a bug or two, but the best tech teams across the administration and the Postal Service are working hard to make this a success," White House spokeswoman Jen Psaki said on Tuesday. "It will officially launch tomorrow morning. It's in the beta testing phase right now."

Psaki noted that the U.S. Digital Service, which she said was founded after the plagued rollout of healthcare.gov, has been supporting the Postal Service with the site.

More than 700,000 people were accessing COVIDtests.gov at one point on Tuesday, according to the Digital Analytics Program.