Donald Tusk

France warns UK premier of tough time ahead in Brexit talks

France warned British Prime Minister Theresa May at her maiden European Union summit that she would face a tough, unyielding bloc if she sought too many concessions during the negotiations to leave the 28-nation EU.

May briefed her European counterparts on the exit road for Britain and left leaders with many uncertainties about the divorce because Britain has yet to trigger the two-year negotiations for "Brexit" — and confirmed she is unlikely to do so until the end of March.

"It's in the interests of the U.K. and the EU that we continue to work closely together," said May, who immediately faced opposition.

French President Francois...