Cyberattacks are a mutual concern for China and the United States, and both countries have agreed to address this global issue, the presidents of the two nations said on Friday after the first meeting of their two-day summit in California.

President Xi Jinping told reporters after meeting with US President Barack Obama that cybersecurity is a shared concern, and that China and the US need to work together to address it.

He said China is a victim of cyberattacks, too, and a firm defender of cybersecurity.

Through genuine cooperation, China and the US can remove suspicion, Xi said, adding that working together on cybersecurity could be a bright spot in future cooperation.

Obama said the US and China should reach a "firm understanding" on Internet issues, and that the two leaders and countries will have further discussions.

"Because of the incredible advances in technology, the issue of cybersecurity and the need for rules and a common approach are going to be increasingly important," he said.

Xi said the two countries have agreed to form a work group under the framework of the China-US strategic security dialogue.

The next annual talks will involve hundreds of government officials and experts from both sides, and the dialogue will be on a wide range of issues related to bilateral relations.

Xi noted that the cybersecurity issue had drawn a lot of media attention in the run-up to his meeting with Obama.

It is claimed that the websites of China's Ministry of Defense and People's Liberation Army receive an average of 144,000 attacks a month from overseas, of which 62.9 percent are from the US.

Li Hong, secretary-general of the China Arms Control and Disarmament Association, said the work group is a positive step for both sides to address a thorny issue, but a breakthrough will need more sincerity from the US.

Crystal Chang, a lecturer of sociology and Asian studies at the University of California Berkeley, said cybersecurity is the most pressing issue facing not only the Sino-American relationship but also the international community.

Because cyberwarfare is not well defined in the international arena, the rules of engagement are unclear, she said.

"What constitutes an attack by one country on another?" she said. "What type of attack should be considered an act of war, and what type of response does it warrant? We don't have answers to these very important questions."

The US and China have an opportunity to work together and lead the world in these matters, Chang added.