China's move to include two United States defense companies on its Unreliable Entity List over their involvement in arms sales to China's Taiwan region was legal, said the Ministry of Commerce on Friday.

The two companies - Lockheed Martin Corp and Raytheon Missiles & Defense - have repeatedly conducted weapon sales to China's Taiwan region in disregard of the country's strong opposition in recent years, severely undermining China's national security, sovereignty and territorial integrity, a ministry spokesperson said in an online statement.

There is no need for foreign-invested companies to worry as these rules are targeted at a few foreign entities that have violated the law. The rules of the list will not arbitrarily expand their scope, according to the ministry.

The spokesperson reiterated that the Chinese government unswervingly promotes high-level opening-up, firmly upholds the multilateral trading system, and protects the legitimate rights and interests of various market entities.

China has clearly stated that greater efforts should be made to attract and utilize foreign capital. The government will make greater efforts to welcome enterprises from all over the world to invest and start businesses in China, and make more efforts to build a market-oriented, legalized and internationalized business environment, said the statement.

China's decision is in line with the World Trade Organization rules. The country has always supported multilateral trading system represented by the WTO, upheld free trade, and promoted the healthy growth of the global economy and trade.