“We call on Iran to halt any further actions which threaten regional stability, and urge diplomatic solutions to de-escalate tensions,” said the statement released by the United States on Monday as Secretary of State Mike Pompeo met Saudi and Emirati leaders.

The four countries renewed concerns about an attack by Yemen’s Iran-aligned Huthi rebels on a civilian airport in southern Saudi Arabia and recent sabotage of ships which Washington blamed on Iran.

“These attacks threaten the international waterways that we all rely on for shipping. Ships and their crews must be allowed to pass through international waters safely,” the four countries said of the Gulf incidents.