Japan remains eager to host Chinese Premier Li Keqiang before the year is out, even as territorial tensions flare in the East China Sea with a pick up in military ships and planes traversing the area.

Top government spokesman Yoshihide Suga said Japan is working toward a summit with Li and South Korean President Park Geun-hye. The system of a rotating annual meeting involving the three countries stalled in 2012 amid recriminations with Japan over wartime history.

"I have absolutely no worries on that score," the chief Cabinet secretary said in an interview in Tokyo on Saturday. "Of course it will happen by the year-end, because we've made a commitment."