In his first public speech since being appointed as CIA chief, Pompeo on Thursday said WikiLeaks was often abetted by other countries, adding that the group had "no moral compass."
He claimed that - rather than opposing dictators and autocratic regimes - WikiLeaks founder Julian Assange was guilty of siding with them.
"WikiLeaks walks like a hostile intelligence service and talks like a hostile intelligence service," Pompeo said.
"I am quite confident that had Assange been around in the 30s, and the 40s and the 50s, he would have found himself on the wrong side of history. We know this because Assange and his ilk make common cause with dictators today."
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Pompeo said that while WikiLeaks claimed to be a champion of freedom, its members were more interested in their public profile.
"They try unsuccessfully to cloak themselves and their actions in the language of liberty and privacy, but in reality, they champion nothing but their own celebrity. Their currency is click bait. Their moral compass - non existent."
Red faces for US officials
Last month, WikiLeaks published almost 8,000 documents saying they revealed secrets about CIA cyber espionage tools. Previously, it released 250,000 State Department cables and embarrassed the US military with logs from Iraq and Afghanistan.
US intelligence agencies claim Democratic emails released by WikiLeaks during the 2016 presidential campaign had originally been hacked by Russia to swing the election against Democratic candidate Hillary Clinton - in favor of Republican Donald Trump. WikiLeaks founder Julian Assange has denied that the release was intended to influence the election.
Before the November election, Trump said he was happy to see WikiLeaks publish private and politically damaging emails from Clinton campaign manager John Podesta.
Assange, from Australia, has been taking refuge in the Ecuadorian embassy in London since 2012, after allegations of rape in Sweden, which he denies. Assange claims the proceedings are being used as a pretext to allow for his extradition to the US.
rc/bw (AFP, AP Reuters)