North Korea has suggested that Japan be removed from six-party talks aimed at its nuclear disarmament.
A commentary in a Pyongyang newspaper said Japan kept creating trouble and had "obstructed" the process.
Japan has refused to grant North Korea the economic and energy aid it seeks as part of a negotiated agreement.
Tokyo says Pyongyang has failed to properly investigate the fate of Japanese citizens abducted in the 1970s and 1980s.
Countries involved in the six-party process are North and South Korea, Russia, China, Japan and the United States.
An agreement was reached in February 2007, in which North Korea agreed to halt all its nuclear activity in exchange for aid and other concessions.
Pyongyang was to receive one million tonnes of energy aid from the five other countries in return for disabling its nuclear plants.
It began dismantling its main nuclear complex last November, and blew up the main cooling tower in a symbolic gesture of its commitment to the process.
Complication
A row which threatened to derail the accord was narrowly averted last week, when the US announced it was removing Pyongyang from its list of state sponsors of terrorism.
Pyongyang wanted to be removed from the list in order to receive international aid and loans, and facilitate its diplomatic rehabilitation.
But Japan criticised the move as "extremely regrettable", saying it wanted North Korea to provide more information about Japanese abductees before Pyongyang was removed from the list.
