U.S. President Barack Obama entered the fray on Wednesday on cyber attacks from China, saying some intrusions affecting U.S. firms and infrastructure were “state sponsored”.

The comments appeared to step up the rhetoric against China following similar remarks from other members of the U.S. administration.

“What is absolutely true is that we have seen a steady ramping up of cyber security threats. Some are state sponsored. Some are just sponsored by criminals,” said Mr. Obama in an interview with ABC News.

“We’ve made it very clear to China and some other state actors that, you know, we expect them to follow international norms and abide by international rules. And we’ll have some pretty tough talk with them. We already have,” said Mr. Obama, complaining that billions of dollars and industrial secrets were lost as a consequence of hacking.

Offensive capabilities

The comments by the President come after a series of warnings from U.S. security officials that Washington would not stand idly by in the face of these threats.

General Keith Alexander, who heads the U.S. National Security Agency and Cyber Command, told lawmakers on Tuesday that the military is creating at least 13 units which would have offensive capabilities in cyberspace as part of efforts to protect U.S. infrastructure.

James Lewis, a specialist at the Centre for Strategic and International Studies, said the heightened rhetoric suggests Washington’s patience has worn thin with China and some other governments .

Mr. Obama was scheduled to meet later Wednesday at the White House with key U.S. business leaders “as a part of the administration’s ongoing dialogue with the private sector regarding cybersecurity”, said a White House statement.

The President will discuss a recent executive order and would “solicit the CEOs’ input on how the government and private sector can best work together to improve the nation’s cyber security”.

China earlier Wednesday said it was willing to cooperate with the U.S.