More than 6,000 cases of monkeypox have now been reported from 58 countries in the current outbreak, the World Health Organization has said.
The WHO will meet to discuss declaring the outbreak a global health emergency, the UN agency's highest level of alert, by July 18.
At its previous meeting on June 27, a WHO committee decided the outbreak, which has seen cases rising both in the African countries where it usually spreads and globally, was not yet a health emergency.
WHO director general Tedros Adhanom Ghebreyesus said a lack of testing meant that cases were going unreported, with more than 80 per cent of the cases in Europe.
"I continue to be concerned by the scale and spread of the virus across the world," Dr Tedros said.
Monkeypox, a usually mild viral infection that causes flu-like symptoms and skin lesions, has been spreading worldwide since early May.
The fatality rate in previous outbreaks of the strain in Africa sits at 1 per cent, while this outbreak is currently less lethal in non-endemic countries.
This week New South Wales health authorities urged people to be aware of the symptoms of monkeypox following the likely transmission of the virus within Australia.
Reuters/ABC