North Korea will not reissue working visas to two American Christian professors at the Pyongyang University of Science and Technology (PUST), the Washington D.C. based Voice of America reported on Tuesday.

Robert and Sandra-Lee Moynihan – who taught business and economics at PUST from August to November last year – were supposed to teach in Pyongyang again from March this year, but were told that North Korea would not provide them with visas for a second tenure at the school.

The two professors, both of whom are practising Christians, contacted the school’s principle and other officials at the technical school