As a scheduled U.S. travel ban to North Korea edges closer to its September 1 implementation date, uncertainty about whether exemptions will allow certain regular visitors to continue working in the country remains high.

The “geographical travel restriction,” which will prohibit U.S. citizens from using their passports for travel to or within North Korea, has been designed with an exemption system to allow approved individuals from four categories to continue visiting.

But with at least 13 not-for-profits, businesses and educational institutions regularly visiting or based in North Korea, as well as dozens of U.S