Tokyo has voiced concern to Paris over a French defense contractor's sale of a copter-stabilization system to China, saying it could aid Beijing's efforts to exert its claim over the disputed Senkaku Islands in the East China Sea, Chief Cabinet Secretary Yoshihide Suga said Monday.

"We are facing a very severe environment around the (Japan-held) Senkakus. So we have expressed (such concerns) to the French government," Suga told reporters, assuring that the sound Japan-France relationship will not be affected by the deal, which wasn't subject to the EU's embargo on arms sales to China.

The major daily Asahi Shimbun reported Monday that French firm DCNS has sold to the Chinese government a system to stabilize a helicopter trying to land on a ship by linking a bar extended from the chopper and deck landing equipment.

Tokyo is worried that the system will help Chinese choppers safely take off and land on marine patrol ships even in bad weather, expanding the scope of Chinese government ships around the Senkaku Islands.

According to the article, DCNS sold two sets of the system to China. Paris has said the system won't be used for military purposes.

Information from Kyodo added