President-elect Joe Biden on Friday slammed the Trump administration's distribution of Covid-19 vaccine as a "travesty."

"Vaccines give us hope, but the roll-out has been a travesty," Biden told reporters in Wilmington, Delaware.

He said distribution of the vaccine would be "the greatest operational challenge we will ever face as a nation."

A Biden spokesman told CNN on Friday the administration would release every available dose of Covid-19 vaccine produced in the country, rather than holding back half the supply to make sure people receive their booster shots on time.