Japan and China opened the ninth round of discussions on a disputed gas field exploration in the East China Sea on Tuesday in Tokyo, accoridng to dpa. Negotiators from the two nations aim to settle a plan to jointly develop gas fields by this fall. They have already agreed on the joint project, but disagreement remains in the location of the exploration. Since Japanese Prime Minister Shinzo Abe and Chinese Premier Wen Jiabao met in Tokyo in April, the two governments agreed to accelerate their gas exploration talks with a target to compile a plan by this fall. Delegates from both countries met at the eighth round of talks in Beijing last month and explained their respective views, but nothing concrete was decided. Japan last year proposed a joint gas field venture on both sides of what it sees as the countries' sea border. China does not recognize the border proposed by Japan and claims an area that stretches further to the edge of the continental shelf, reaching as far as the Okinawa Trough.