Johnson announced the tough new stay-at-home order for England that takes effect at midnight Tuesday and won't be reviewed until at least mid-February.

The prime minister said the country is at "a critical moment," with cases rising rapidly in every part of the country.

Brexit, in essence, takes place at the strike of midnight Thursday in Brussels -- an hour earlier London time -- when the U.K. leaves de-facto membership of the European Union.

Businesses were scrambling Monday to digest the details and implications of the 1,240-page deal sealed by the EU and the U.K. on Christmas Eve.

From Canada to India, one nation after another banned flights from Britain, while France barred the entry of trucks from Britain for 48 hours while the strain is assessed.

Johnson's office also confirmed plans to begin a nationwide COVID-19 vaccination program next month, assuming regulators approve a vaccine against the virus.

A month-long lockdown is going into effect in England, while four Italian regions, including Milan, designated as 'red zones,' will face a partial shutdown from Friday.

The comments came as Johnson gave the House of Commons details of the proposed four-week lockdown in England that is set to begin Thursday.

The lockdown announced Saturday by Prime Minister Boris Johnson is to run from Thursday until Dec. 2.

Johnson is expected to set out a new system of "local COVID alert levels" of medium, high or very high, aimed at helping tailor restrictions for different parts of England.