China has played down a threat by Google to quit the country on hacking and censorship concerns, but the United States says, it will formally express concern over the cyber attacks the internet search giant said originated in China. A spokesman for China's Commerce Ministry says, there are many ways to resolve the Google issue, but has repeated that all foreign companies, Google included, must abide by Chinese laws. Yet the US State Department says, it will ask China to explain the attacks. The issue risks becoming another irritant in China's relationship with the United States, already strained by arguments over the Chinese currency's exchange rate, trade protectionism and US arms sales to Taiwan. Washington has long been worried about Beijing's cyber-spying program. A congressional advisory panel said in November that the Chinese government appeared increasingly to be penetrating US computers to gather useful data for its military.