(SALZBURG, Austria) — Britain and its European Union partners failed on Thursday to secure a breakthrough in Brexit talks, largely because of seemingly intractable divisions over the best way to avoid a hard border on the island of Ireland and how to deal with future trade. With Britain’s departure from the EU looming — March 29, 2019 — there are growing concerns that a deal on the post-Brexit relationship may not be cobbled together in time to ensure a smooth and orderly British exit. Despite reports of a friendly spirit at the meeting, the fundamental differences remained, said EU Council President Donald Tusk after chairing a summit in Salzburg, Austria. All leaders, including British Prime Minister Theresa May, are desperate to solve the biggest Brexit riddle — how to keep goods moving freely between Northern Ireland in the U.K.