China undermines international efforts to force Iran and North Korea to halt their nuclear programs, a panel of US experts charged Wednesday in an annual report for the US Congress.

The US-China Economic and Security Review Commission also warned that Beijing would look to destroy or takeover US space assets and try to hack into military computers in any conflict with "technologically superior" Washington.

The 400-page report comes as anger runs high in the US Congress over China's allegedly unfair trade practices, its expanding global influence, and its economic ties to North Korea and Iran, two nations Washington wants to isolate.

"Chinese support for North Korea and Iran demonstrates China's willingness to place its national interests ahead of regional stability by providing economic and diplomatic support to countries that undermine international security," it said.

Beijing "shields" Pyongyang from diplomatic pressure and trades and invests with the secretive regime, giving it "an economic lifeline in the face of growing international ostracism," according to the report.

"Beijing's continued support for Pyongyang is primarily driven by its fear of a collapse of the North Korean regime and the consequences this would have for China's economic, social, and security interests, as well as the fear of the loss of a buffer state on its border," it said.

China is "a large investor" in Iran's energy sector and "major provider" of refined petroleum products, while supplying Tehran "with advanced conventional weapons, such as cruise missiles," all in potential violation of US law.

The commission highlighted 10 of its 43 recommendations to lawmakers as especially important, including investigating whether Chinese firms doing business with Iran faced the appropriate US sanctions.

It also urged Congress to assess the Pentagon's ability to operate "in a degraded command, control, communications, computer, intelligence, surveillance, and reconnaissance environment for an extended period of time."

Lawmakers should also test the Pentagon's readiness to handle "the destruction, denial, degradation, or manipulation of US space assets" and the impact on communications, navigation, intelligence, and other functions.

"China has identified the US military's reliance on information systems as a significant vulnerability and seeks to use Chinese cyber capabilities to achieve strategic objectives and significantly degrade US forces' ability to operate."

The commission urged lawmakers to press US President Barack Obama to "employ all necessary remedies" allowed under World Trade Organization (WTO) rules "to counter the anticompetitive and trade-distorting" policies of China.

With US unemployment stubbornly hovering above nine percent, US lawmakers have accused China of keeping its currency -- and thus its exports -- artificially cheap, while tolerating rampant theft of US intellectual property and promoting homegrown firms in the awarding of government contracts.

The commission also called for the United States to sell Taiwan state-of-the-art fighter jets, and urged a top-to-bottom review of US policies towards mainland China, to be led by Obama's national security council.