The United States continued Wednesday to voice concern about cyber attacks from China and other countries, with a leading U.S. lawmaker comparing such attacks to the terrorist threat the United States faced on September 11, 2001.

However, U.S. House of Representatives' Homeland Security Committee chairman Michael McCaul told lawmakers that U.S. officials are aware of the cyber threats, which have targeted U.S. media, energy projects, air traffic control systems and technology companies. He also said U.S. authorities are taking steps to counter such attacks.

Hours earlier, President Barack Obama, speaking on U.S. television, said some attacks on U.S. firms and infrastructure have originated in China and are state sponsored.

For its part, the Chinese Foreign Ministry says Beijing is open to cyber security talks, while insisting that China is a victim and not a perpetrator of such crimes.

McCaul, writing last week in the Wall Street Journal, cited a January report by the U.S. cyber security firm Mandiant which identified China as the source of nearly 90 percent of cyber attacks targeting the United States. He said such attacks have also come from Iran and Russia.

He also detailed what he said was an Iranian attack on the Saudi state-owned Saudi Aramco energy company, and said the goal of the attack was stopping Saudi oil production. He additionally described multiple denial-of-service attacks on major U.S. banks that he said also originated in Iran.

The New York Times last month published evidence linking one of the most active Chinese attack groups to a neighborhood in Shanghai that is also headquarters to a major cyber unit of the People's Liberation Army. The report said the account was based on unclassified work done by Mandiant, and said it echoed findings from intelligence agencies that have been tracking the Chinese attackers.