TAIPEI (Taiwan News) — The United States blacklisted 24 Chinese companies and targeted individuals on Wednesday (Aug. 26) for helping China build man-made islands in the disputed South China Sea.

The U.S. Commerce Department added the two dozens companies to the Entity List “for their role in helping the Chinese military construct and militarize the internationally condemned artificial islands in the South China Sea.” In addition, the U.S. Department of State said it would begin imposing visa restrictions on Chinese individuals connected with the building of the disputed outposts.

The trade sanction bars U.S. firms from exporting products to the 24 Chinese companies without a government license, according to the Washington Post. A senior Commerce Department official said U.S. exports to the targeted firms have only been around US$5 million in the last five years, Reuters reported.

The companies placed on the Entity List include several businesses related to the China Communications Construction Company (CCCC), Guangzhou Haige Communications Group, Beijing Huanjia Telecommunication, China Electronics Technology Group Corporation, China Shipbuilding Group, and Shanghai Cable Offshore Engineering. Two of the firms — the CCCC and the China Electronics Technology Group Corporation — are major contractors in Beijing’s Belt and Road Initiative, which builds infrastructure in developing nations, the Washington Post reported.

Since 2013, Beijing has dredged and constructed more than 3,000 acres of artificial islands equipped with anti-ship missiles and air defense equipment, according to the Commerce Department and State Department statements.

China claims nearly all of the South China Sea as its own, an area of about 3.6 million square kilometers, based on a vague nine-dash line map. In 2016, a tribunal at the Permanent Court of Arbitration dismissed China’s claims to the waters as having no merit; however, Beijing refused to accept or recognize the ruling.