Hackers, mainly from China, have recently been targeting US firms to steal confidential data, which is why the US now considers cyber attacks to be its top security threat.

China, which has consistently denied being behind the attacks, says it is ready to co-operate on the issue.

The White House has accused Chinese hackers of attacking the country's interests.

On Wednesday, Barack Obama, the US president, will meet corporate leaders to discuss how they can work together to improve cyber security.

Al Jazeera's Alan Fisher reports from Washington.

Source: Al Jazeera