The WHO says that another 50 suspected cases are being investigated, without naming any countries.
Earlier, infections were confirmed in Italy, Sweden, Spain, Portugal, the US, Canada and the UK - where the first European case was reported.
Monkeypox is most common in remote parts of Central and West Africa.
It is a rare viral infection which is usually mild and from which most people recover in a few weeks, according to the UK's National Health Service.
The virus does not spread easily between people and the risk to the wider public is said to be very low.