John Kerry warns Europeans not to ‘go off half-cocked’

Secretary of State John F. Kerry urged European Union leaders Monday to avoid political theatrics and “revengeful” infighting as they cope with the uncertainties surrounding Britain’s departure from the 28-member bloc.

“It’s critical as we go forward in these next days to understand the importance of a strong EU,” Mr. Kerry told reporters during a stop in Brussels, where he met with EU High Representative Federica Mogherini before heading to London on Monday afternoon.

“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,” he said.

Britain’s historic vote in a referendum last week to leave the EU marks the first time that a nation has divorced itself from the bloc — a move that has brought wider European unity into question at levels not seen in decades.

“The United States cares about a strong EU,” said Mr. Kerry, who appeared with Ms. Mogherini for a brief public statement in Brussels, where EU leaders are slated to gather Tuesday to begin the unprecedented departure proceedings for Britain.

He stressed that Washington is working closely on a host of issues with the EU, from responding to climate change, to counterterrorism, migration and immigration.

“You name it, we are working together,” Mr. Kerry said.

The goal now, he said, should be to find “ways to maintain the strength that will serve the interests and the values that brought us together in the first place. … That’s what is important.”