The Trump administration imposed sanctions on the Chinese military on Thursday for buying fighter jets and missile systems from Russia, in breach of a sweeping U.S. sanctions law punishing Moscow for meddling in the 2016 U.S. election.
In Beijing, the Chinese government expressed anger and demanded the sanctions be withdrawn.
The U.S. State Department said it would immediately impose sanctions on China's Equipment Development Department (EDD), the military branch responsible for weapons and equipment, and its director, Li Shangfu, for engaging in "significant transactions" with Rosoboronexport, Russia's main arms exporter.
The sanctions are related to China's purchase of 10 SU-35 combat aircraft in 2017 and S-400 surface-to-air missile system-related equipment in 2018, the State Department said.
They block the Chinese agency, and Li, from applying for export licenses and participating in the U.S. financial system.
It also adds them to the Treasury Department's list of specially designated individuals with whom Americans are barred from doing business.
The U.S. also blacklisted another 33 people and entities associated with the Russian military and intelligence, adding them to a list under the 2017 law, known as the Countering America's Adversaries Through Sanctions Act, or CAATSA.
CAATSA also seeks to punish Russia for its aggression in Ukraine and involvement in Syria's civil war.
"China expresses strong indignation at these unreasonable actions by the U.S. side and has already lodged stern representations," Chinese Foreign Ministry spokesman Geng Shuang told reporters in Beijing, adding the moved seriously harmed bilateral relations and military ties.
"We strongly urge the U.S. side to immediately correct the mistake and rescind the so-called sanctions, otherwise the U.S. side will necessarily bear responsibility for the consequences," he said, without giving details.
China has "normal" military exchanges and cooperation with Russia, aimed at protecting regional peace and stability, which is not against international law or aimed at any third party, Geng added.
China will continue to work with Russia to promote strategic cooperation at an even higher level, he said.
Doing significant business with anyone on the U.S. blacklist can trigger sanctions like those imposed on China.
Some of those added to the list, which now contains 72 names, were indicted in connection with Russian interference in the 2016 U.S. election, a U.S. official said.
President Donald Trump on Thursday issued an executive order intended to facilitate implementation of the sanctions.
A federal special counsel is leading a criminal investigation of Russian interference in the U.S. election, and any possible cooperation with Trump's presidential campaign.
Trump has insisted there was no collusion with Russia. Moscow denies any effort to meddle in U.S. politics.