"This is the first step in completely closing all levels of contact with South Korea, and ending everything unnecessarily," said a newsreader on the state-run North Korean TV channel KCNA. 

- There is no need to sit eye-to-eye with the South Korean authorities, and nothing to discuss, as they have only aroused our dissatisfaction.

Sent criticism with balloon

Recently, North Korean representatives have been annoyed by defectors in the South sending regime-critical leaflets across the border with the help of balloons. South Korean officials have said they tried to stop the balloons.

There are around 50 direct lines between North and South Korea. In 2016 and 2018, the direct lines were also turned off. During that period, North Korea tested warheads on several occasions, and North Korea's dictator Kim Jong-un had a war of words with President Trump, including via Twitter. 

During periods when North Korea does not respond to contact attempts from South Korea, South Korea still continues to call.