The US has officially withdrawn from the World Health Organization (WHO), leaving the UN agency without one of its biggest donors.

US President Donald Trump signed an executive order signalling the withdrawal a year ago, having criticised the organisation for being too "China-centric" during the Covid pandemic.

The US Department of Health and Human Services said it took the decision due to the WHO's alleged "mishandling" of the pandemic, an inability to reform and political influence from member states.

The WHO has rejected these claims and its director general Tedros Adhanom Ghebreyesus said the withdrawal was as a loss for the US and the world.

The organisation pointed to its global efforts to combat polio, HIV aids, maternal mortality, and its international treaty on tobacco control.

In the wake of the pandemic, WHO member states worked to create an international pandemic treaty designed to prevent, prepare for, and respond to future pandemics, including sharing vaccines and drugs more fairly.

The treaty was finally agreed in April last year by all WHO member states, apart from the US.

Washington has traditionally been one of the biggest donors to the WHO, but has not paid its fees for 2024 and 2025, which has already caused huge job losses at the organisation.

Although WHO lawyers suggest the US is obliged to pay the arrears - estimated at $260m (£193m) - Washington said it saw no reason to do so.

It said that all US government funding to the WHO has been terminated, US personnel and contractors have been recalled from the WHO headquarters in Geneva, Switzerland and its offices worldwide, and hundreds of US engagements with WHO have been suspended or discontinued.

"The WHO tarnished and trashed everything that America has done for it," a joint statement from US Health Secretary Robert F Kennedy and Secretary of State Marco Rubio read.

The pair said the organisation had "abandoned its core mission and acted repeatedly against the interests of the United States", including failing to return the American flag based at its Geneva headquarters.

"Going forward, U.S. engagement with the WHO will be limited strictly to effectuate our withdrawal and to safeguard the health and safety of the American people," they added.

The US department said it would have bilateral relations with other countries to ensure disease surveillance and pathogen sharing, but were unable to provide information about which specific countries they had such links with so far.

In response to a question about global efforts to combat polio or HIV, officials said the US would partner with "NGOs and faith based groups" to continue that work, but could not give details of any partnerships yet established.

Asked whether the US would continue to participate in information sharing for and development of the annual global flu vaccine, officials were not sure.

After Trump signed the withdrawal order at the start of his second term, the WHO wrote that it hoped the US would reconsider, and said the "WHO and the USA have saved countless lives and protected Americans and all people from health threats".

Its reconsideration would have been for the "benefit of the health and well-being of millions of people around the globe", it concluded.

The WHO said on Friday that the US withdrawal was on the agenda for its upcoming board meeting from 2-7 February.

It told the BBC that its secretariat will act according to the advice from the governing bodies.