Prime Minister Boris Johnson was to chair a crisis meeting Monday as a growing number of countries from France to Argentina blocked flights to Britain over a new highly infectious coronavirus strain the UK said was "out of control".
The World Health Organization also called for stronger containment measures across Europe, which has passed 500,000 deaths from Covid-19.
But there was positive news across the Atlantic where US lawmakers reached a deal for a nearly $900 billion Covid-19 financial package to help struggling Americans.
In London, Johnson called the COBR emergencies committee meeting to "discuss the situation regarding international travel, in particular the steady flow of freight into and out of the UK", a spokesman said.
More than a dozen European nations have already banned flights and travellers from Britain, with more expected to take action.