Pyongyang, July 21: US President Barack Obama has expressed concerns over increasing cases of cyber-attacks, calling it the ‘most serious economic and national security’ challenge that America faces.

In an opinion piece for the Wall Street Journal, Obama pointed out that the US had to do more to put essential defences in place to avoid the debilitating effects of an attack.

“It would be the height of irresponsibility to leave a digital backdoor wide open to our cyber-adversaries,” Obama wrote in the newspaper’s editorial column.

He warned enemies struggling to defeat the US on the terrestrial battlefield might move the conflict to cyberspace, the BBC reports. According to the report, Obama rehearsed the potential consequences of a successful cyber-attack, saying it could trigger a financial crisis if banks were hit.

Health emergencies could be caused by infiltrating the computer systems in hospitals or water treatment plants, he said. And taking out power plants could bring entire regions to a standstill, he added. (Agencies)