BANGKOK (AP) — Japan has protested against Chinese controls that will limit its exports of a key chemical used to make computer chips, saying Tuesday that Tokyo is studying the potential impact on Japanese companies.

China imposed the curb on imports of dichlorosilane from Japan, saying its exports of the material, also known as DCS, have violated anti-dumping regulations and harmed China’s domestic industry.

Beginning Tuesday, companies importing the chemical compound from Japan must provide cash deposits to China’s customs at rates of up to 99.2%. The measure applies to Shin-Etsu Chemical and Denal Silane, among other Japanese exporters of DCS.

Beijing says the measure is provisional as an investigation continues. A final ruling will come later.

Relations between China and Japan have been strained since November, when Japanese Prime Minister Sanae Takaichi angered Beijing by suggesting Japan's military could intervene if China used military force on Taiwan, a self-ruled island Beijing claims as its territory.

In Tokyo, Japan’s top government spokesperson, Chief Cabinet Secretary Minoru Kihara, protested against the controls and said Tokyo would “respond appropriately” to avoid unfair harm to Japanese companies.

China’s commerce ministry launched its anti-dumping probe into Japanese DCS as part of various measures against Japan. Beijing has also imposed export controls on Japanese firms for dual-use items that can be used for military purposes.

DCS is used in a chemical vapor process to put thin layers of silicon, oxide, or other films in semiconductor logic and memory chips. The global market for DCS is highly competitive, but Japan is the leading producer of ultrapure DCS for computer chip fabrication.

___

Yamaguchi reported from Tokyo.