Mr Pompeo told MPs that his criticism of Mr Tedros was based on “firm intelligence foundation” but he did not disclose what information he was referring to, according to The Times.
It came as Dominic Raab, the UK’s foreign secretary, denied that Britain had been “strong-armed” by the US into taking a tougher stance against China.
Mr Rabb was asked on Tuesday whether the UK’s recent positions on China, such as the decision to exclude Huawei from its 5G network, had been influenced by the Trump administration.
“I don’t think there is any question of strong-arming – Mike [Pompeo] and I always have constructive discussions and actually a vast majority of the times our views overlap and we work together very well,” he told a news conference in London.
US secretary of state Mike Pompeo has claimed the head of the World Health Organisation (WHO) has been “bought” by China and suggested that his failings have led to the deaths of British people, according to reports.
Mr Pompeo reportedly told MPs that the WHO was a “political, not a science-based organisation” and said the body was responsible for “dead Britons”.
It is understood the Trump official made the claim about Dr Tedros Adhanom Ghebreyesus at a private meeting with MPs during his visit to the UK on Tuesday.
The allegations are the latest in a string of attacks on the WHO by the Trump administration, which formally withdrew from the body earlier this month over its handling of the coronavirus pandemic.
Mr Pompeo has called on countries, including the UK, to form a coalition to put pressure on China to change its political course.
“We think that the entire world needs to work together to ensure that every country – including China – behaves in the international system in ways that are appropriate and consistent with the international order,” the secretary of state said.
He also welcomed the UK’s responses to China over Huawei and the introduction of a controversial national security law in Hong Kong.
The US official, who held talks with Boris Johnson and Mr Raab on Tuesday, said he had seen “Hong Kong’s freedoms crushed” and “watched the Chinese Communist Party bully its neighbours”.
“I want to take this opportunity to congratulate the British government for its principled response to these challenges,” he added.
In recent weeks, the UK has banned Huawei from its 5G network, put forward plans to allow British National Overseas (BNO) passport holders in Hong Kong to come to the UK, suspended its extradition treaty with Hong Kong and extended an arms embargo on China.
Donald Trump tried to claim credit last week for the UK’s move to ban Huawei, when he said in a White House briefing that he had convinced ”many countries” to stop using the Chinese technology company.
“It’s a big security risk. I talked many countries out of using it. If they want to do business with us, they can’t use it,” Mr Trump said.
On the topic of Huawei, Mr Pompeo said he thought the UK had made a “good decision” but dismissed suggestions that the White House’s negative opinion of the company was the deciding factor in the move.