Visitors to North Korea will no longer be able to apply for a visa waiver program when they visit the U.S.

According to the Foreign Ministry on Tuesday, the U.S. government began enforcing the rule this week, retroactively applying it to all foreign passport holders who visited North Korea since March 2011.

At present, nationals from 38 countries, including South Korea, may visit the U.S. for up to 90 days after obtaining online approval via the Electronic System for Travel Authorization(ESTA), a visa waiver program.

However, from Tuesday, visitors to North Korea will have to apply for a standard visa before visiting the U.S.

Although inter-Korean travel is illegal for most South Koreans, some 37-thousand Korean passport holders received special government approval to visit North Korea between March 2011 and July 2019.

Among these are Samsung Electronics Vice Chairman Lee Jae-yong and SK Group Chairman Chey Tae-won, who accompanied President Moon Jae-in for an inter-Korean summit in Pyongyang last September. 

According to the U.S. government, the ESTA exclusion is in line with Washington's redesignation of North Korea as a state sponsor of terrorism in late 2017.