According to AP, US President Donald Trump has sent a personal letter to North Korean leader Kim Jong Un, seeking to maintain good relations and offering cooperation in fighting the viral pandemic.

In a statement carried by the Korean Central News Agency, Kim's sister and senior ruling party official, Kim Yo Jong, praised Trump for sending the letter at a "time when big difficulties and challenges lie ahead in the way of developing ties” between the countries.

But, it is not a good idea to make a hasty conclusion or be optimistic about the prospect for bilateral relations, she said.