The World Health Organization (WHO) cautioned that the time to contain outbreaks of the monkeypox virus in non-endemic countries is dwindling. 

"The risk of monkeypox becoming established in non-endemic countries is real," WHO director-general Tedros Adhanom Ghebreyesus warned at a briefing on Wednesday.

"But, that scenario can be prevented," he noted. "WHO urges the affected countries to make every effort to identify all cases and contacts to control this outbreak and prevent onward monkeypox spread."

The United Nations health agency said that there have been more than 1,000 reported cases across 29 countries in the current outbreak outside countries in Africa, where the disease most commonly spreads. 

No deaths have been reported.

MONKEYPOX GUIDANCE: CDC DELETES CALL FOR MASKS ON TRAVELERS

More cases of monkeypox were reported around the U.S., bringing the total tally up to 40. 

According to data from the Centers for Disease Control and Prevention (CDC), New York now has nine reported cases of the virus and California has eight. 

Florida remains at four and Illinois and Colorado have three.

Utah, Hawaii and the District of Columbia each recorded two cases. 

Arizona, Georgia, Massachusetts, Pennsylvania, Texas, Virginia and Washington state all have one.

CDC RAISES MONKEYPOX ALERT TO LEVEL 2, RECOMMENDS MASKS DURING TRAVEL

On Monday, the agency raised its alert level for monkeypox to level 2, warning people to practice "enhanced precautions." 

Although the majority of new monkeypox cases have been seen in gay or bisexual men, experts caution that anyone is at potential risk. 

People normally become infected with the monkeypox virus through contact with the skin lesions or bodily fluids of infected animals or humans or through contact with materials contaminated with the virus.

Rosamund Lewis, the WHO technical lead on monkeypox, said that the risk of aerosol is not yet fully known, and instructed health workers treating monkeypox patients to wear a mask. 

The CDC told Fox News on Tuesday that it recommends masking in high-risk situations in countries where there is a current monkeypox outbreak.

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Monkeypox, which is related to smallpox, has milder symptoms

Some of those symptoms include fever, chills, rash and aches, before lesions develop. 

Reuters contributed to this report.