WASHINGTON - The White House is finalizing details with the U.S. Postal Service to deliver 500 million coronavirus test kits to households across the country, according to four people familiar with the plans, kick-starting a key part of President Joe Biden's response to the raging omicron variant. 

The administration will launch a website allowing individuals to request the rapid tests, those people said, speaking on the condition of anonymity to discuss private planning sessions. Officials aim to begin shipping the kits by mid-January.

Test manufacturers and distributors seeking to provide a share of the 500 million tests have submitted proposals to the government, and the Biden administration on Thursday evening awarded its first contract toward the purchase, said a person with knowledge of the testing plan. A formal announcement on the effort could come as soon as next week.

The Postal Service is currently negotiating with its four labor unions to extend the seasonal workforce - the roughly 40,000 people brought in each year to help the agency work through a glut of holiday packages. The agency moved 13.2 billion pieces of mail and parcels between Thanksgiving and New Year's Eve.

A White House representative declined to comment for this report. Representatives from the Postal Service did not immediately respond to requests for comment.

The demand for testing has far outstripped supply in recent weeks as millions of Americans traveled during the holiday season while the highly contagious omicron variant began to spread. Biden announced on Dec. 21 that his administration would purchase and distribute 500 million rapid tests - as scenes played out across the country of people lining up outside pharmacies to purchase tests or at community centers where some local governments distributed them to residents.

Earlier that month, as shortages began, White House press secretary Jen Psaki played down the idea of mailing federally procured tests around the country.

"Should we just send one to every American?" she asked sarcastically at a Dec. 6 news briefing. "Then what happens if every American has one test? How much does that cost, and then what happens after that?"

Jeffrey Zients, the White House's coronavirus response coordinator, told reporters Wednesday that manufacturers would begin delivering tests to the federal government "over the next week or so." He said those kits would "not disrupt or in any way cannibalize the tests that are on pharmacy shelves and on websites and used in other settings."

New confirmed infections in the United States have roughly quadrupled since Biden first announced his plan to send rapid tests to Americans, rising from about 155,467 cases on Dec. 21 to nearly 611,000 cases on Tuesday, the highest total of the pandemic, according to The Washington Post's rolling seven-day average.

The Postal Service has been floated before as a potential mechanism in the nation's pandemic response. The Trump administration had plans to ship 650 million reusable cloth face masks to every U.S. household as early as April 2020, when the country was recording fewer than 30,000 new cases per day. The agency had gone as far as to draft a news release about the program and even selected the communities where the first shipments would arrive.

But then-President Donald Trump nixed the plan over a running feud with postal leadership and a concern that sending the masks "might create concern or panic," according to a Trump administration official.

Talks between the Biden administration and postal leaders began in late December and accelerated after Christmas, said the four people involved in the planning.