The 12 players crossed the border with an official delegation and will start training with the team from the South.

In a breakthrough deal, both countries last week agreed to field a joint team to compete under a single flag.

It marks a thaw in relations that began in the new year, when North Korea said it wanted to attend the Games.

The deal had been met with some criticism in the South, as it might mean there will be less time on the ice for the South's player.

On Saturday, the International Olympic Committee (IOC) agreed that the 12 players could be added to the South's full team of 23 players.

"It is a tough situation to have our team be used for political reasons, but it's kind of something that's bigger than ourselves right now," Sarah Murray, the coach of the South Korean team, told a news conference on Monday.

North Korean state media on Thursday said "all Koreans at home and abroad" should work towards unification without the help of other countries.

Participation in the Games is seen as an effort by Pyongyang to ease tensions on the peninsula in the face of growing international pressure and sanctions over its nuclear and missile programmes.

North Korea was originally not expected to attend the Games in the South.

But leader Kim Jong-un unexpectedly suggested in a new year address that his country might join after all, leading to a flurry of meetings with the South and the IOC.

North Korea will now send a total of 22 athletes to the Olympics, which open on 9 February

Along with the hockey players, a figure skating pair and several speed skaters and skiers will compete.

Pyongyang will be sending a large delegation including a cultural troupe to perform during the Games as well as a smaller delegation to the Paralympics in March.

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