North Korea opened a massive resort area on its east coast, the country's state media said on Wednesday, with the tourism project reportedly set to welcome Russian guests next month.

Dubbed "North Korea's Waikiki" by South Korean media, the Wonsan Kalma Coastal Tourist Area can accommodate nearly 20,000 people, according to Pyongyang, which previously described it as "a world-class cultural resort".

The tourist zone opened to domestic visitors on Tuesday, Pyongyang's official Korean Central News Agency reported, publishing images of tourists in colourful swimsuits enjoying the beach.

North Koreans of all ages from across the country flocked to the site this week "filled with joy at experiencing a new level of civilization", KCNA reported.

The visitors were "astonished by the grandeur and splendour of the tourist city, where more than 400 ... artistically designed buildings lined the white sandy beach in ideal harmony", it added.

According to South Korea's Yonhap news agency, a group of Russian tourists is set to visit the zone in North Korea for the first time on July 7.

South Korea's unification ministry, which manages relations with the North, said the site's operations are "expected to gradually expand", including to Russian tourists.

The country's leader Kim Jong-un said last week the construction of the site would go down as "one of the greatest successes this year" and that the North would build more large-scale tourist zones "in the shortest time possible".

Previously released images showed him sitting in a chair – alongside his teenage daughter Ju-ae and wife Ri Sol-ju – watching a man flying off a water slide in the resort. (AFP)