The Obama administration’s top diplomat told representatives of the European Union on Monday that they should not go off “half-cocked” or “loses their head” now that Britain has voted to leave the collective of European nations.

“I think it is absolutely essential that we stay focused on how, in this transitional period, nobody loses their head, nobody goes off half-cocked, people don’t start ginning up scatterbrained or revengeful premises, but we 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 after a meeting with EU officials in Brussels. “And that’s what is important.”