China firmly opposes any country in any form selling arms to Taiwan and building military links with Taiwan, said Hua Chunying, a spokesperson for the Chinese Foreign Ministry, during a regular press briefing on Monday while answering a question about companies from the U.S., Europe, Japan, and India helping Taiwan build its own submarines. 

Hua also urged relevant countries to fully recognize the sensitivity of the matter and earnestly abide by the one-China policy.

Relevant enterprises' participation in Taiwan's submarine program, as well as military contact with Taiwan, should all be forbidden, Hua said. 

The spokesperson warned all concerned parties to be discreet and avoid undermining peace and stability across the Taiwan Strait and their bilateral relations with China.