New COVID-19 restrictions in the Chinese area bordering North Korea may have scuttled Kim Jong Un’s plans to reopen a vital crossing that has been closed for almost two years.

The Chinese border city of Dandong this week asked residents not to leave unless necessary due to a flareup of COVID-19 cases in nearby Zhuanghe. "The risk of an epidemic spreading is very high,” Dandong disease control officials said in a statement Monday.

The statement came the same day that a North Korean train crossed into Dandong, South Korean broadcaster KBS reported, showing a video of what it said were carriage cars passing over a bridge between the neighbors. And it was now unclear whether North Korean trains would be able to return anytime soon, the NK News website reported, citing Dandong residents.