NKorean hockey players arrive in SKorea

A busload of North Korean ice hockey players have gone to South Korea to begin training for the Winter Olympics.

A bus carrying North Korean ice hockey players crosses the border northwest of Seoul. (AAP)

A delegation of North Korean officials and ice hockey players has crossed the heavily guarded border into South Korea on Thursday for joint Olympics training.

The group includes 12 North Korean players who will form a combined women's ice hockey team with their southern counterparts at next month's Winter Olympics in the South Korean resort of PyeongChang.

Under an agreement worked out during the first official talks between the two Koreas in two years, the joint team will wear unity jerseys and march under a unified peninsula flag at the Games' opening ceremony on February 9.

Earlier on Thursday, North Korea sent a rare announcement addressed to "all Koreans at home and abroad", saying they should make a "breakthrough" for unification without the help of other countries, its state media said.

All Koreans should "promote contact, travel, cooperation between North and South Korea" while adding Pyongyang will "smash" all challenges against reunification of the Korean peninsula.

Some South Korean opposition politicians and conservatives have criticized Pyongyang's participation in the PyeongChang Games, saying Kim was using North Korea's involvement for his own purposes.