Canada has issued a monkeypox travel notice, advising visitors to more than two dozen countries, including Australia, Britain and the United States, to take precautions and warning of potential delays returning home if they fall ill.

In a level-two notice - one grade below a call to avoid non-essential trips - the Public Health Agency of Canada said travellers may be subject to procedures to limit the spread of monkeypox, such as isolation, should they become infected.

"You may have limited access to timely and appropriate health care should you become ill, and may experience delays in returning home," the agency said on Twitter.

About 30 countries where monkeypox is not endemic have reported outbreaks of the viral disease in recent weeks, with more than 911 confirmed or suspected infections, mostly in Europe.

Canada has confirmed 81 cases of the disease, most of which were recorded in its second-most-populous province of Quebec.

Monkeypox, which spreads through close contact, mostly occurs in west and central Africa and has only very occasionally spread elsewhere.