New York City Mayor Bill de Blasio announced the imposition of a vaccine mandate for private sector employees Monday.

Speaking MSNBC, de Blasio said that the mandate was in response to the emergence of the Omicron coronavirus variant and would take effect on December 27.

De Blasio said that the mandate would be the first of its kind in the US.

"We’re leading the way and taking bold steps to combat COVID," he said.