HALIFAX -- A senior American security official has suggested it remains to be seen whether China will honour an agreement reached this year on state-sponsored cyberattacks on private businesses.

The United States and China have "core differences" on the subject, Admiral Michael Rogers, the director of the U.S. National Security Agency and head of the United States Cyber Command, told the Halifax International Security Forum on Saturday.

"The Chinese practice of using the capabilities of the state directed against private companies in order to generate an economic advantage for Chinese business, we have argued, is a fundamentally unacceptable practice," Rogers said during a panel discussion on international relations with China.

President Barack Obama and Chinese President Xi Jinping met in September and agreed not to conduct or knowingly support cyber theft of trade secrets or competitive business information. The agreement applies only to state-sponsored cyberattacks that target businesses.

Rogers said he was surprised the Chinese government agreed in the first place.

"(China has) gained significant economic benefit by the practices they have employed and they have been resistant to change," he said.

"We're two months into this and we'll see how this plays out over time."

A few weeks after the agreement, California-based cyber security company CrowdStrike Inc. said it detected at least seven Chinese online attacks against U.S. technology and pharmaceutical companies that appeared aimed at theft of intellectual property and trade secrets.

Earlier this year before the leaders reached the agreement, it was revealed the Office of Personnel Management, which posts U.S. government job opportunities, was the victim of what American officials said they believe was a Chinese espionage operation that affected an estimated 21.5 million background check records used for security clearances.

It's in China's long-term interest to end state-sponsored cyberattacks against western companies, Rogers told the panel, but did not elaborate as to why.

Rogers noted that China is "increasingly every bit as vulnerable as any other industrialized nation-state" to cyberattacks.

The U.S. could consider criminal charges or sanctions against China if it's determined hackers are violating the agreement not to conduct economic cyber-espionage on American industry.

There were no Chinese representatives during the panel discussion. The Chinese embassy in Ottawa did not immediately respond to an email.