The US government has become the target of a Chinese cyber attack aimed specifically at the State Department, official sources told AFP on Wednesday.

According to IT giant Microsoft, the target of the attack was the email accounts of several federal agencies, referring to an actor who is “based in China and whom Microsoft calls Storm-0558”.

Microsoft did not name the targets, but a State Department spokesman said Wednesday that the department responsible for shaping U.S. diplomacy was affected.

“The State Department has detected anomalous activity and has taken immediate steps to protect our computer systems and will continue to closely monitor the situation,” he said, without elaborating.

“In terms of cyber security, we are not disclosing what our response was and the incident is under investigation,” he added.

President Joe Biden’s national security adviser, Jake Sullivan, told ABC that the hacking activity was “discovered pretty quickly.”

“We managed to avoid further violations,” he said.

The new cyber attack comes as the United States and China, which are in fierce competition, have resumed contacts at the highest level after months of tension, including during a visit by the secretary of state to the United States.