China says it has protested to the US for putting Chinese companies and individuals on a new sanctions list targeting Iran.

Foreign Ministry spokesman Lu Kang said on Monday Beijing had "lodged representations" with Washington after Trump's administration imposed sanctions on 25 people and entities on Friday for trade with Iran.

"We have consistently opposed any unilateral sanctions," Lu told a regular press briefing in Beijing.

Unilateral US sanctions in the past have infuriated China. Last March, Beijing was outraged after the US government punished China’s largest telecom equipment maker ZTE Corps for alleged violations of sanctions on Iran.

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China irate as US targets Iran trade

China's Foreign Ministry expressed anger at the action, saying it is “opposed to the US citing domestic laws to place sanctions on Chinese enterprises."

The new US sanctions list includes two Chinese companies and three Chinese people. Those on the list cannot access the US financial system or deal with American companies.

They are subject to secondary sanctions, meaning foreign companies and individuals are prohibited from dealing with them or risk being blacklisted by the United States.

China has close economic and diplomatic ties with Tehran. Executives of two Chinese companies included on the list said they had only exported "normal" goods to Iran and didn't consider they had done anything wrong. Lu said such sanctions, particularly when they harmed the interests of a third party, were "not helpful" in promoting mutual trust.

China's Foreign Ministry spokesman Lu Kang

China has said it is "seriously concerned" about President Donald Trump's recent hawkish rhetoric on Beijing. Experts say the new administration’s moves are set to further strain relations between China and the US.