China summoned the US ambassador and the Defense Ministry warned Tuesday of "serious damage" to military relations after the United States charged five Chinese army officers with hacking into US companies to steal vital trade secrets.
China's response marked a rapid escalation in a dispute that has deeply angered Beijing over US claims that the Chinese military is illegally helping the country's massive state industries.
China has already strongly denounced the charges and said it was suspending cooperation with the US in a joint cybersecurity working group. The group was formed last year in the wake of allegations of Chinese military involvement in online commercial espionage. China has stridently denied the allegations.
State-run Xinhua News Agency said Tuesday that Chinese Assistant Foreign Minister Zheng Zeguang called US Ambassador Max Baucus to a meeting Monday night.
Zheng lodged a "solemn representation with the US side," Xinhua said, using standard diplomatic language for a complaint. A US Embassy spokesman said he had no immediate comment.
A statement issued by the Foreign Ministry Monday night said the charges were based on "fabricated facts" and would jeopardize China-US "cooperation and mutual trust."
"China is steadfast in upholding cybersecurity," said the statement, which was read again Tuesday on state television's midday news broadcast. "The Chinese government, the Chinese military and their relevant personnel have never engaged or participated in cyber-theft of trade secrets. The US accusation against Chinese personnel is purely ungrounded and absurd."
In its statement, the Defense Ministry repeated the charges, but added that the US accusations would send a chill through gradually warming relations between their two militaries.
"Up to now, relations between the China-US militaries had been development well overall," the ministry said. "The US, by this action, betrays its commitment to building healthy, stable, reliable military-to-military relations and causes serious damage to mutual trust between the sides."
The Chinese and US have launched a series of initiatives to reduce mutual suspicion and smoothen communication. However, US criticism of China's territorial assertions in the South China Sea and support for Japan and other Chinese rivals have consistently generated frictions.
The hacking charges represent the biggest challenge to bilateral relations since an unprecedented private summit between President Barack Obama and his counterpart Xi Jinping last summer.
The Chinese targeted big-name American makers of nuclear and solar technology, stealing confidential business information, sensitive trade secrets and internal communications for competitive advantage, according to a grand jury indictment that the Justice Department said should be a national "wake-up call" about cyber intrusions.