Taiwan protested Tuesday over a Philippine plan to explore oil and gas in disputed waters in the South China Sea where Taipei claims sovereignty.
"The Reed Bank is part of the Spratly islands... and we reject any claim or occupation by any means of the islands and the surrounding waters," the Taiwanese foreign ministry said in a statement.
According to the ministry, the Philippines is planning to accept bidding to explore and drill for oil and gas in the Reed Bank.
In Manila, a spokeswoman for President Benigno Aquino on Tuesday insisted on her country's right to the disputed area.
"We maintain that Recto Bank is within the territorial jurisdiction and is undisputed," Abigail Valte told reporters, using the Filipino name for Reed Bank.
Taiwan, the Philippines, Vietnam, Brunei, China and Malaysia claim all or part of the Spratlys, which could lie on top of large oil reserves.
All claimants except Brunei have troops based on the archipelago of more than 100 islets, reefs and atolls, which have a total land mass of less than five square kilometres (two square miles).
The Taiwanese coastguard currently has a 130-strong garrison on Taiping, the biggest island in the Spratlys archipelago.
Taiwan's security chief has called for Taipei to commit more military resources in the Spratlys, reacting to reports that rival claimants to the disputed waters are building up their armed presence.