US President Donald Trump has downplayed the seriousness of a long-running and widespread data breach across the US government, and questioned whether Russia was to blame.
"The Cyber Hack is far greater in the Fake News Media than in actuality," Mr Trump said on Twitter on Saturday.
"Russia, Russia, Russia is the priority chant when anything happens because Lamestream is, for mostly financial reasons, petrified of discussing the possibility that it may be China (it may!)."
Mr Trump's assertion that China may be behind the hacking spree, which has so far affected more than half a dozen federal agencies including the Commerce and Treasury Departments, runs counter to comments by his own Secretary of State and multiple politicians briefed on the matter.
"We can say pretty clearly that it was the Russians that engaged in this activity," Secretary of State Mike Pompeo said on Friday.
A State Department spokesperson did not immediately respond to a request for comment.
"The cyber hack is like Russian bombers have been repeatedly flying undetected over our entire country," Republican Senator Mitt Romney said in a tweet on Thursday.
The Kremlin has denied any involvement.
In his tweet, Trump tagged Mr Pompeo and Director of National Intelligence John Ratcliffe.
The Office of the Director of National Intelligence has yet to publicly comment on who is behind the massive data breach, which exploited a piece of software developed by network management firm SolarWinds that is widely used throughout the public and private sectors.
Networking gear maker Cisco Systems said a limited number of machines in some of its labs had been found with malicious software on them, without saying if anything had been taken. A person familiar with the company's ongoing probe said fewer than 50 were compromised.
A small number of organisations were also compromised in Britain but not in the public sector, a security source said.
Shares in cyber security companies FireEye, Palo Alto Networks and Crowdstrike Holdings rose on Friday as investors bet that the spate of disclosures from Microsoft Corp and others would boost demand for security technology.
The breaches of US government agencies hit the Department of Homeland Security, the Treasury Department, State Department and Department of Energy.
The US Treasury Department building viewed from the Washington Monument. Source: AAP
In some cases the breaches involved monitoring emails but it was unclear what hackers did while infiltrating networks, cybersecurity experts said.
