African countries raised an objection on Tuesday to a US-led proposal to reform the International Health Regulations (IHR), a move delegates say might prevent passage at the World Health Organization's (WHO's) annual assembly.

If Africa continues to withhold support, it could block one of the only concrete reforms expected from the meeting, fraying hopes that members will unite on reforms to strengthen the UN health agency's rules as it seeks a central role for itself in global health policy.

The IHR set out WHO members' legally binding obligations around outbreaks. The United States has proposed 13 IHR reforms which seek to authorise the deployment of expert teams to contamination sites and the creation of a new compliance committee to monitor implementation of the rules.

The draft proposal yet to be formally decided is seen as the first step in a broader IHR reform process and would aim to change article 59 that would speed up the implementation for future reforms from 24 to 12 months.

But the African group expressed reservations about even this narrow change, saying all reforms should be tackled together as part of a "holistic package" at a later stage.

"The African region shares the view that the process should not be fast tracked...," Moses Keetile, deputy permanent secretary in Botswana's health ministry, told the assembly on Tuesday on behalf of the Africa region.

Diplomats said that African objections may be a strategy to seek concessions on vaccine and drug-sharing from wealthier countries who were seen to be hoarding supplies during Covid-19.

"We find that they are going too quickly and these sorts of reforms can't be rushed through," said an African delegate in Geneva who was not authorised to speak to the media.

The US mission in Geneva did not respond to a request for comment.

Several other countries expressed broad support for the idea of IHR reforms, without giving specifics. Iran and Malaysia also expressed reservations.

One diplomat following the discussions "They don't agree but it's not a disaster. It's a multilateral process so you can't force things through."

The negotiations will run alongside talks on a potential pandemic treaty, raising concerns over duplication. "Several developing countries have said that the WHO has too many platforms for negotiation, and it is simply not manageable," said Nithin Ramakrishnan, consultant for the Third World Network.

Since the US IHR proposal, Russia has also submitted draft revisions, diplomats say. This assembly is expected to officially launch IHR reform discussions, which may last up to two years.