Pyongyang has criticized Washington’s decision to ban US passport holders from visiting North Korea, with state media describing it on Friday as a “sordid” attempt to limit human exchanges.

The North’s KCNA news agency, citing an unidentified spokesman for the foreign ministry, said there was no reason for foreigners to feel threatened while in North Korea.

“Our doors are always open for all Americans who visit our country out of good will and wish to see our reality,” the spokesman said.

The US State Department said earlier this week the ban would take effect on September 1.

It follows the death in June of US student Otto Warmbier, who was sentenced in North Korea last year to 15 years’ hard labor for trying to steal an item bearing a propaganda item from his hotel.

KCNA did not name Warmbier in Friday’s report, but said the North had delivered “just punishment” to some US citizens who had carried out acts against the regime.