US authorities warned Wednesday that Chinese hackers were attempting to steal coronavirus data on treatments and vaccines, adding fuel to Washington's war with Beijing over the pandemic.

The FBI and the Cybersecurity and Infrastructure Security Agency (CISA) said organizations researching COVID-19 were at risk of "targeting and network compromise" by China.

They warned that Chinese government-affiliated groups and others were attempting to obtain "valuable intellectual property and public health data related to vaccines, treatments, and testing."

"China's efforts to target these sectors pose a significant threat to our nation's response to COVID-19," they said.

The two organizations gave no examples to support the allegation.

But the warning added to the battle between the superpowers over the outbreak that began in China and has killed at least 293,000 worldwide, and more than 83,000 in the United States.

President Donald Trump has accused China of hiding the origins of the virus and not cooperating in efforts to research and fight the disease.

Asked on Monday about reports that the US believed Chinese hackers were targeting US vaccine research, Trump replied: "What else is new with China?... I'm not happy."

Spies, academics targeted

The warning Wednesday also underscored that Washington believes China has continued broad efforts to obtain US commercial and technology secrets under President Xi Jinping's drive to make his country a technological leader.

In February the US Justice Department indicted four Chinese army personnel suspected of hacking the database of credit rating agency Equifax, giving them the personal data of 145 million Americans.

On Monday the Department of Justice announced the arrest of University of Arkansas engineering professor Simon Saw-Teong Ang for hiding ties to the Chinese government and Chinese universities while he worked on projects funded by NASA.

The indictment said Ang was secretly part of the Xi-backed Thousand Talents program, which Washington says China uses to collect research from abroad.

Also on Monday Li Xiaojiang, a former professor at Emory University in Atlanta, admitted tax fraud in a case focused on his hidden earnings from China, also as a participant in the Thousand Talents program.

Senator Marco Rubio, a member of the Senate Intelligence Committee, said such cases combined with the coronavirus are forcing China to change its tactics.

"Beijing has shifted its recruitment efforts for the Thousand Talents Program online, and it has increased efforts to hack US medical research institutes for COVID-19 information," he said.

Race for a vaccine

Beijing has repeatedly denied the US accusations.

The FBI warning comes as dozens of companies, institutes and countries around the world are racing to develop vaccines to halt the coronavirus.

Many more groups are researching treatments for infected patients. Currently there is no proven therapy.

An effective vaccine could allow countries to reopen and potentially earn billions of dollars for its creators.

Most expert believe it will take more than a year to get a vaccine fully approved, and much longer to produce enough of it.

Government-backed cyber operators in Iran, North Korea, Russia and China have been accused of pumping out false coronavirus news and targeting workers and scientists.

Britain said last week it had detected large-scale "password spraying" tactics -- hackers trying to access accounts through commonly used passwords -- aimed at healthcare bodies and medical research organizations.

Sanctions, compensation

Increasingly US officials are discussing punishing China and seeking compensation for the costs of the pandemic.

In April the US state of Missouri sued China's leadership over what it described as deliberate deception and insufficient action to stop the virus.

On Tuesday Republican senators proposed legislation that would empower Trump to slap sanctions on China if Beijing does not give a "full accounting" for the coronavirus outbreak.

"Their outright deception of the origin and spread of the virus cost the world valuable time and lives as it began to spread," Senator Jim Inhofe said in a statement.