DUBLIN, April 10 (Xinhua) -- European Council President Donald Tusk said on Tuesday that people are concerned about the peace process in Northern Ireland after Brexit, according to local media reports.

Tusk made this remark while addressing a meeting at University College Dublin (UCD) here on Tuesday evening. He came to Dublin to receive an honorary lifetime membership of the UCD Law Society after a short visit to Belfast to mark the 20th anniversary of the Good Friday Agreement, a multilateral agreement signed among the British, Irish governments as well as political parties in Northern Ireland on April 10, 1998, which ended the decades-long violence in Northern Ireland.

"While here in Dublin and in Belfast today, on the 20th anniversary of the Good Friday Agreement, thousands of people are looking with concern and anxiety to the future of the peace process after Brexit," Tusk said in his 15-minute speech to hundreds of students gathering at the O'Reilly Hall of the UCD Law Society.

"I don't like Brexit. Actually,that's an understatement.I believe Brexit is one of the saddest moments in the 21st century European history. In fact, sometimes I am even furious about it," said Tusk.

He said that it needs much effort, suffering and time to build peace and unity and it would take little time and effort to undermine and demolish this structure.

Warning of the potential for conflict in Europe, he called on Europe to unite.

"Only a united Europe can be a sovereign Europe in relation to the rest of the world. Only a united Europe guarantees independence for its nations, guarantees freedom for its citizens," he said, adding that "The unity of Europe is not a bureaucratic model. It is a set of common values and democratic standards."

Tusk also said that "This year will be about Brexit, mainly, unfortunately. Instead of integration, I will be dealing with disintegration, in fact, some kind of damage control process, and my main focus will be to eliminate or at least reduce negative side effects of Brexit, with the Irish question, of course, in the centre of my attention."

He said that European and British negotiators are seeking a solution to avoid a hard border between Ireland and Britain's Northern Ireland after Brexit, an issue which is believed to be a source of potential conflict if not handled properly.