North Korea has banned American citizens holding dual nationality from entering the country, marking a reversal from an earlier policy allowing U.S. nationals to circumvent restrictions by using passports from other countries.

In a blog post published Wednesday, a travel agency specializing in tours to North Korea said the restriction applies to all U.S. visitors, including those looking to travel for tourism, business or sporting events in the DPRK.

“The restriction comes into effect immediately with applicants being checked for any links to U.S. citizenship during the visa approval process,” Young Pioneer Tours (YPT) said. “Individuals found to hold American