China on Friday once again stressed that it does not accept Japan's claim of a so-called "median line" in the East China Sea.

"China did not recognize it in the past. China does not recognize it now and will not in the future," Chinese Foreign Ministry spokesman Qin Gang said in response to questions concerning a ship traffic ban around the Pinghu gas field.

Qin said China and Japan have never conducted a demarcation of the East China Sea. "The so-called 'median line' is an unilateral claim by the Japanese side and it has no legal force."

The Chinese maritime authorities had posted a notice that all unauthorized ship traffic would be banned from March 1 to September 30 in the waters around the Pinghu field due to construction. On April 18, the notice was re-posted with an amendment to the operation areas.

Qin said earlier this week that the correction was due to a "technical inaccuracy".

However, some Japanese press claimed the change showed that the "median line" had become a "fact".

Qin rebutted such reports, saying that they were wishful thinking.

The spokesman said China issued the notice according to an international pact and domestic laws in a bid to ensure the work safety at the operation areas and the traffic safety of ships passing by the region.

He said the work area in the notice was defined according to the capacity of the operational watercraft and it completely accords with international laws and practices.