US research group 38 North says Pyongyang is preparing for a military parade as part of the ruling Workers' Party congress which is now under way.
The group released satellite images of the suburbs of Pyongyang taken on December 31.
It said the images showed over 400 large vehicles and a number of troop formations training along the practice route.
The group said, however, that the upcoming parade may be on a smaller scale than the one held last October. That parade was held to celebrate the 75th anniversary of the ruling party's inauguration.