US Secretary of State John Kerry addressed students at Korea University in Seoul on Monday (18 May) to promote the importance of international cyber stability.

Kerry urged responsible nations to take action against worldwide cyber attackers in his speech, which comes shortly after the US Defense Department's unveiling of an updated cyber strategy that stresses the US military's ability to retaliate with cyber weapons and deter attacks.

Earlier in the day, Kerry pointed the finger at North Korea's behaviour on the international stage, saying the country had "not even come close" to taking the steps needed to rein in its nuclear weapons programme to initiate talks.

At Korea University, Kerry said the US reserved the right to use all necessary means, including economic, trade and diplomatic tools, as deemed appropriate in order to defend the nation and its partners, friends, and allies.

"The sanctions against North Korean officials earlier this year, are one example of the use of such a tool in response to DPRK's (Democratic People's Republic of Korea) provocative, destabilising and repressive actions, including the cyber attack on Sony Pictures. Now as the international community moves towards consensus about what exactly constitutes unacceptable behaviour in cyber space, more and more responsible nations need to join together to act against disruptors and rogue actors," he said.

Kerry emphasised cooperation and consensus in cyber space in the search for cyber stability.

"Worldwide, the risk and frequency of such attacks is on the increase. America's policy is to promote international cyber stability. The goal is to create a climate in which all states are able to enjoy the benefits of cyber space, all have incentives to cooperate and avoid conflict, and all have good reason not to disrupt or attack one another. To achieve this we are seeking a broad consensus on where to draw the line between responsible and irresponsible behaviour. As I've mentioned, the basic rules of international law apply in cyber space," he added.

Earlier this year, US President Barack Obama issued an executive order authorising expanded sanctions against North Korea in the wake of the hacking of Sony Pictures Entertainment, which Washington blamed on Pyongyang.

The sanctions targeted three companies as well as 10 North Korean government officials, including individuals working in Iran, Syria, China, Russia and Namibia, according to the Treasury Department.