China has decided to add two United States defense companies - Lockheed Martin Corp and Raytheon Missiles & Defense - to its Unreliable Entity List in response to their involvement in arms sales to Taiwan island, the Ministry of Commerce said on Thursday.

This move is aimed at safeguarding China's national sovereignty, security, and development interests, the ministry's bureau of industry, security, import and export control said in an online statement.

As a result of the decision, the listed companies will be prohibited from engaging in import and export activities with China and their senior management personnel will be banned from entering the country.

Lockheed Martin and Raytheon Missiles will not be allowed to invest within China and they will be fined an amount equivalent to twice the value of their contracts related to the sale of arms to Taiwan island since the implementation of China's Unreliable Entity List rules.

The two US companies have 15 days to pay the fine, and may face additional penalties if this decision is not complied with after the deadline. The new measures will come into effect immediately.