North Korea has threatened Japan over Tokyo's policy of heaping pressure on its nuclear-armed neighbor, saying it "may not get a ticket for Pyongyang" if it continues, remarks that come just days after Japanese government sources said the country is exploring the possibility of a summit between Prime Minister Shinzo Abe and North Korean leader Kim Jong Un.

"Now is a high time that Japan meditated over its policy toward the DPRK, facing up to the trend of the times for itself," the North's state-run Korean Central News Agency said in a commentary late Saturday, using the country's formal name.

"We have already warned that the Japanese reactionaries may not get a ticket for Pyongyang if they go ill-natured without discretion. It would be wise for them to stop useless struggling and follow the trend of the times, before it is too late," it added.