The US has tightened the enforcement of international sanctions in a way that will increase compliance costs for many shipping companies.

Without changing the wording of sanction orders, the Department of the Treasury has issued two advisories detailing how companies should avoid dealings with Iranian, Syrian and North Korean shipments.

“There are several organizations that provide commercial shipping data, such as ship location, ship registry information and ship flagging information,” says one advisory. “This data should be incorporated into due diligence best practices.”