Brussels should avoid the temptation to embrace “revengeful premises” after British voters chose to leave the European Union in last week’s referendum, U.S. Secretary of State John Kerry said Monday.

EU leaders need to ensure that during the exit negotiation with the U.K., “nobody loses their head, nobody goes off half-cocked, people don’t start ginning up scattered-brained or revengeful premises,” Kerry said, after a meeting with European Commission President Jean-Claude Juncker and High Representative for Foreign Affairs Federica Mogherini in Brussels.

Instead, European and American leaders must “look for ways to maintain the strength that will serve the interests and the values that brought us together in the first place,” Kerry said.

While the result of Britain’s EU referendum was not the result that President Obama and Kerry had hoped for, European leaders must “implement [it] in a way that is responsible, sensitive, thoughtful and I hope strategic,” the secretary of state said.

“The United States care about a strong EU,” Kerry said, citing global challenges on which the EU and the U.S. work together, such as climate change, counterterrorism and migration.

“At the same time, the U.S. will maintain its special and strong relationship with Great Britain,” Kerry said.