The US Centers for Disease Control and Prevention has said it is aware of over 700 global cases of monkeypox, including 21 in the United States, with investigations now suggesting it is spreading inside the country.

Axar.az reports that all patients are in recovery or have recovered, and no cases have been fatal.

"There have also been some cases in the United States that we know are linked to known cases," Jennifer McQuiston, deputy director of the CDC's Division of High Consequence Pathogens and Pathology, told reporters on a call on Friday.

"We also have at least one case in the United States that does not have a travel link or know how they acquired their infection."