European Union leaders are debating the future of their bloc as Britain eyes the exit door and far-right parties look to get strong results in upcoming elections, and will be hoping Friday to quickly heal a new rift with Poland.

The 27 leaders, minus British Prime Minister Theresa May, gathered at EU headquarters a day after Donald Tusk was re-elected to a second term in one of the bloc's most prestigious jobs over the objections of Poland, his homeland.

Discussions Friday are to focus on the 27 leaders' summit in Rome later this month to mark the 60th anniversary of the EU's founding treaty, and how to maintain unity amid severe political and migration pressure.

The leaders are weighing how a future EU should operate; whether it should limit itself to being a trade bloc, steam toward a federal super-state or allow some members to advance at different speeds when practical.

An immediate concern, though, was moving past Thursday's spat with the nationalist government in Warsaw, which was alone in trying to block Tusk — a former Polish prime minister and bitter political rival — as president of the EU Council. Poland then refused to approve some summit texts.

"I am convinced that this will be an episode," Austrian Chancellor Christian Kern said. "I see no sense, either for the Poles or the rest, in going to sulk in a corner."

Europe must concentrate on matters of substance — jobs, economic growth, migration and security — "and there are good approaches from which I think we have a good chance of finding a consensus among the 27," he said.

Luxembourg's prime minister made clear that frustration with Poland lingered, saying that "behavior like yesterday's is not acceptable."

"I don't think yesterday will be the long-term state of the EU," Xavier Bettel said. "I am convinced that Poland will become sensible again in the coming days and weeks."