Neither agency cited any specific examples Wednesday, but they warned that institutions and companies involved in work on vaccines, treatments and testing for the novel coronavirus should take additional security measures to protect data and be aware of the potential threat.

China's efforts to target these sectors pose a significant threat to our nation's response to COVID-19, said a statement from the U.S. Cybersecurity and Infrastructure Security Agency.

This announcement is intended to raise awareness for research institutions and the American public and provide resources and guidance for those who may be targeted." It comes amid heightened tensions between the two countries over the source of the outbreak and Trump administration complaints that China did not adequately alert the world to the danger posed by the new coronavirus.

The warning also echoes long-standing U.S. complaints that China has engaged in the wholesale theft of technology and trade secrets to build its economy.

Institutions that have received media attention for their efforts related to COVID-19, the disease caused by the coronavirus, should assume that they would be targeted and should take precautions, the Department of Justice said.

The potential theft of this information jeopardizes the delivery of secure, effective, and efficient treatment options, it said. The FBI and the cybersecurity agency said they were issuing the alert to raise public awareness of the potential threat and said additional technical details would be released in the coming days.

China has defended its response to the virus, and Foreign Ministry spokesman Zhao Lijian denied the government was involved in any attempt to steal virus-related data on Monday, after some media reported on the warning in advance.

We are leading the world in COVID-19 treatment and vaccine research, Zhao told reporters. It is immoral to target China with rumors and slanders in the absence of any evidence.