President of the European Council, Donald Tusk, speaks during a press conference in Brussels, March 18, 2016. GETTY IMAGES/CARL COURT

European Union President Donald Tusk said in an interview published Monday that voting to leave the 28-member bloc would be a geopolitical setback for Britain. He also said it would take at least seven years to negotiate a new Britain-EU relationship.

Britain will hold a referendum on June 23 to decide whether it should leave or remain in the EU. In the interview with German newspaper Bild, Tusk said a vote to leave “would be a setback not just economically but above all geopolitically for Britain,” the Associated Press reported.

Even though he was wary of commenting on the long-term implications of the move, he feared that “Brexit could be the beginning of the destruction not just of the EU but of the entire political civilization of the West.”

However, European Parliament Vice President Alexander Lambsdorff said earlier this month: “A European Union without Germany or France is completely unimaginable, but we had a European Union without Britain at the very beginning.”

“It won’t be the end of ‘Project Europe’, as some are describing it,” he added.

The UK Independence Party has been advocating Brexit, claiming that Britain’s development was being held back by the country being a part of EU. The “remain” camp, on the other hand, claims that U.K. is more secure as a part of a bigger regional system.

British Prime Minister David Cameron, who leads the latter, earlier this year negotiated a deal with EU leaders that would grant the Britain “special” status within the 28-nation bloc if it chooses to stay in the union.

Many, including the Group of Seven leaders, have warned that a British vote to leave the EU would be a serious risk to global economic growth. The European Union would also have to change its voting structure to adjust to Britain’s departure.

Tusk said cutting treaty links between Britain and the EU and negotiating a new relationship would take at least two years and five years respectively.