The United States Treasury Department on Tuesday rescinded temporary sanctions waivers that permitted Iran to export oil after Tehran attacked three ships in the Strait of Hormuz, raising new concerns about maritime security and threatening a fragile peace agreement with Washington.

The Treasury Department’s Office of Foreign Asset Control’s decision ends a 60-day general license issued on June 21 that permitted the production, sale, delivery, and transport of Iranian crude oil and petroleum products as part of negotiations aimed at securing a broader peace agreement with Tehran.