A group of senior U.S. and China cyber officials on Wednesday held its first meeting since the two countries struck an anti-hacking agreement in September to try to ease years of acrimony over the issue.

The so-called Senior Experts Group on International Norms and Related Issues is expected to gather twice a year, the U.S. State Department said in a statement announcing the meeting.

It provided scant information about the talks, saying officials from the two nations' foreign, defense and other ministries discussed "international norms of state behavior and other crucial issues for international security in cyberspace."

China withdrew in 2014 from a separate bilateral cyber working group following the U.S. indictment of five members of its military on charges it hacked six U.S. companies. The new group appears be a fresh start to grapple with cyber issues.

Cyber security has long been an irritant in relations between China and the United States, despite robust economic ties worth nearly $600 billion in two-way trade last year.

The September pact, reached during a U.S. visit by Chinese President Xi Jinping, included a pledge that neither country would knowingly carry out hacking for commercial advantage.