LONDON (AP) — Ireland's prime minister says Brexit is the challenge of a generation, and "unique solutions" will be needed to prevent it doing major damage.

Leo Varadkar said Friday that a so-called "hard Brexit," in which Britain leaves the EU single market, would mean "barriers to commerce and trade" between EU member Ireland and Northern Ireland, part of the U.K.

Britain is due to leave the EU in March 2019. EU officials say progress must be made on resolving issues around the Irish border, the size of Britain's exit bill and the status of EU nationals in the U.K. before Britain and the bloc can start hammering out their future economic relationship.

Varadkar says he hopes EU leaders will see enough progress by a summit in October, but time is running out.