An EU official said leaders heard that the "probability of a no deal is higher than of a deal" at a brief discussion of Brexit at a Brussels summit, as time ticks down to a Sunday deadline to make a call on prolonging talks or giving up.

The pessimistic tone came after British Prime Minister Boris Johnson warned Thursday there was a "strong possibility" of no deal, and instructed his government to prepare for Britain to crash out of the European Union's single market at the end of this year.