Taiwan “does not recognize this unilateral move that will provoke disputes and sternly reaffirms its territorial claim” to the South China Sea, the foreign ministry said in a statement.
“We urge neighboring countries to exercise self-restraint and avoid any unilateral moves that will affect peace and stability in the region, instead replacing confrontation with dialogue,” it said.
Philippine President Benigno Aquino said Wednesday his government would register the new name with the United Nations as part of efforts to delineate its sovereign territory, a move that could further raise tensions with China.
China claims nearly all of the South China Sea, even waters approaching the coasts of other countries.
Ships from China and the Philippines engaged in a stand-off at Scarborough Shoal, a tiny group of islands in the sea, earlier this year, and the Philippines says Chinese vessels remain there.
Brunei, Malaysia and Vietnam also claim all or part of the Spratlys Islands – an area in the South China Sea thought to contain large oil reserves.
The rival claims have long made the South China Sea one of Asia’s potential military flashpoints, and tensions have escalated over the past year.