BEIJING, June 10-- China has reprimanded the United Statesfor hosting the head of Taiwan's opposition Democratic Progressive Party (DPP), which is known for its advocacy of Taiwan independence.

DPP chair Tsai Ing-wen recently concluded a U.S. visit during which she was received for a meeting at the State Department headquarters.

"The move went against the peace and stability of the Taiwan Strait and harmed peaceful development of cross-Strait ties," said Ma Xiaoguang, spokesperson for the State Council Taiwan Affairs Office, at a regular press conference Wednesday.

Complaining that the meeting "sent a wrong signal to the island's separatist forces," Ma urged the United States to adhere to the one-China principle and oppose Taiwan independence.

"We firmly oppose any person engaging in any form of Taiwan independence separatist activities in the international arena," he said.

Tsai discussed cross-Strait relations during her U.S. visit but -- according to Ma -- failed to make clear what her stance was on the issue. "People of both sides need a clear answer from the DPP," Ma said.

"The Chinese mainland and Taiwan belong to one China and cross-Strait ties are not relations between countries," he added, before warning, "Once the foundation is shaken, peaceful development of cross-Strait relations will be no longer maintained."