WASHINGTON— China’s government must take action to stop the "unprecedented” wave of Chinese cyber-attacks against the US, President Barack Obama’s most senior security aide said on Monday. Tom Donilon, Obama’s national security adviser, used a speech on US relations with Asia to mount the White House’s most aggressive response so far to a series of military-style hacks of US corporations. Describing the problem as "a key point of concern and discussion” at "all levels of our governments”, Donilon said: "Beijing should take serious steps to investigate and put a stop to these activities.” He urged Chinese officials to show "recognition of the urgency and scope of this problem and the risk it poses – to international trade, to the reputation of Chinese industry and to our overall relations”. Donilon’s remarks, to The Asia Society in New York, came amid mounting tensions between Washington and Beijing over a string of cyber-attacks that have been linked to the Chinese military. In his State of the Union address this year, Obama warned that America’s enemies were "seeking the ability to sabotage our power grid, our financial institutions and our air traffic control systems”. He signed an executive order setting standards for corporate computer security and directing US defence and intelligence agencies to share classified information about online threats with businesses. The New York Times, The Wall Street Journal and The Washington Post all disclosed earlier this year that their corporate computer networks had been penetrated by Chinese hackers, who were apparently trying to monitor US coverage of Chinese issues. The attacks on the New York Times coincided with its investigation into the personal wealth of  Wen Jiabao, the outgoing Chinese prime minister. Last month an anonymous-looking tower block in Shanghai was named as the alleged headquarters of hackers working for the Chinese military. A series of large-scale cyber-attacks were traced back to the building, in the Pudong district of the city, by a US cybersecurity firm. China has consistently denied any involvement in the attacks. Chuck Hagel, the new US secretary of defence, has promised to prioritise cybersecurity at the Pentagon, telling a Senate hearing: "It’s insidious, a quiet kind of threat we haven’t quite seen before. It can paralyse a nation in a second.” Donilon said in his speech that US firms were suffering from the "sophisticated, targeted theft of confidential business information and proprietary technologies through cyber intrusions emanating from China on an unprecedented scale”. "The international community cannot afford to tolerate such activity from any country,” he said, promising: "We will take action to protect our economy against cyber-threats.” Congress is currently working on new legislation to improve US defences against a cyber attack, including a requirement for private companies in key industries, like communications and energy, to establish their own cybersecurity systems. The bill will also allow the US government to pass more information to the private sector about possible threats from foreign hackers.