WASHINGTON: White House Press Secretary Jen Psaki said on Monday the delay in sharing coronavirus vaccines with other countries is due to logistical challenges, after the White House laid out a plan to share 55 million U.S. COVID-19 vaccine doses globally.

"What we have found to be the biggest challenge is not actually the supply, we have plenty of doses to share with the world, but this is a Herculean logistical challenge," Psaki said.