WASHINGTON (Reuters) -The White House said it expected the private sector to take the lead on verification of COVID-19 vaccines, or so-called vaccine passports, and would not issue a federal mandate requiring everyone to obtain a single vaccination credential.

The Biden administration was reviewing the issue and would make recommendations, White House press secretary Jen Psaki said on Monday, but she added, “We believe it will be driven by the private sector.”

Japan is gearing up to issue digital health certificates to citizens who have been vaccinated against the novel coronavirus, joining China, the European Union and others that have adopted similar measures aimed at opening up overseas travel, the Nikkei reported on Saturday.

Psaki said the White House was leading an inter-agency process looking at these issues, and would provide guidance in line with several key principles:

“There are a couple key principles that we are working from. One is that there will be no centralized universal federal vaccinations database, and no federal mandate requiring everyone to obtain a single vaccination credential,” she said.

“Secondly, we want to encourage an open marketplace with a variety of private sector companies and nonprofit coalitions developing solutions. And third, we want to drive the market toward meeting public interest goals.”

Psaki said the Biden Administration would work to ensure that all vaccination credential systems met key standards such as universal accessibility, affordability and availability, both digitally and on paper.

She gave no indication when the process would be completed.

(Reporting by Jeff Mason; writing by Andrea Shalal; editing by Chris Reese and Dan Grebler)