China on Thursday warned that Japan would have to take "full responsibility" for any consequences if it proceeds with exploration for oil and gas in a contested area of the East China Sea.

Foreign Ministry spokesman Qin Gang made the remark at a regular news briefing Thursday afternoon, one day after Tokyo announced it would grant Japanese firms concessions to test-drill in the disputed waters nearly halfway between Okinawa and the coast of mainland China.

"What I want to say is that we strongly demand that the Japanese side value the Chinese side's serious concern," Qin said. "The consequences hinge on the Japanese side."