The World Health Organization declared the outbreak of monkeypox to be a public health emergency of international concern.
"The global monkeypox outbreak represents a public health emergency of international concern," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said during a briefing in Geneva Saturday.
At the virtual press conference, Ghebreyesus also said that the outbreak has spread around the world "rapidly," including those that had not seen it before, and that officials understand "too little" about the disease. The risk of monkeypox is moderate globally except in the European region, where the risk is assessed as high, he said.
Ghebreyesus also outlined a set of recommendations for countries that have not yet reported a case of monkeypox or have not reported a case for 21 days; those with recently imported cases of monkeypox that are experiencing human-to-human transmission; those with transmission of monkeypox between animals and humans; and those with manufacturing capacities for diagnostics, vaccines and therapeutics.
This is the seventh event declared a PHEIC by the global health agency since 2007.
The other six include the H1N1 influenza pandemic of 2009; the Ebola outbreak in West Africa from 2013 to 2015; the Ebola outbreak in the Democratic Republic of the Congo from 2018 to 2020; the Zika outbreak in 2016; the ongoing spread of poliovirus that started in 2014; and the ongoing COVID-19 pandemic, according to the National Library of Medicine.
More than 16,000 monkeypox cases have now been detected across the globe in 75 countries and territories, according to the WHO. Thus far, five deaths have been reported, all of which have occurred in Africa.
In the United States, more than 2,800 cases are confirmed in 44 states and the District of Columbia, according to the Centers for Disease Control and Prevention. In New York, which has reported the highest number in the U.S., a total of 900 cases of monkeypox have been confirmed, with the vast majority of them -- 93% -- detected in New York City, state officials said Friday.
U.S. Department of Health and Human Services (HHS) Secretary Xavier Becerra called the WHO's declaration a "call to action for the global health community."
"Monkeypox has spread around the world and we will continue to take decisive action to tackle it both here in the U.S. and, working in concert with our partners abroad, globally," Becerra said in a statement.
He added that the Biden administration plans to "accelerate" its monkeypox response "in the days ahead" -- including making vaccines, testing and treatments available to those who need it.
U.S. health officials had advised that cases will continue to rise amid the outbreak.
"I would like you to all understand that we anticipate an increase in cases in the coming weeks," CDC Director Dr. Rochelle Walensky said during a press briefing last week, noting that with increased testing, an improved reporting system for states and the continued spread of disease, more cases will be identified.
She added, "We know monkeypox symptoms usually start within three weeks of exposure to the virus, so we anticipate we may see an increase in cases throughout the month of July and into August."
Prior to the outbreak, most cases occurred in countries where the virus is endemic -- typically central and western Africa.
Monkeypox is generally a mild illness with the most common symptoms being fever, headache, fatigue and muscle aches. Patients can develop a rash and lesions that often begin on the face before spreading to the rest of the body.
People are typically infected by animals through a bite or a scratch or through preparation and consumption of contaminated bush meat.
However, in the current outbreak, most of the spread has come from coming into contact with infected people's lesions or bodily fluids, making it less transmissible than other viruses such as COVID-19.
Most cases have been reported among men who identify as gay, bisexual or men who have sex with men, though experts have emphasized anyone can be infected. There is currently no evidence monkeypox is a sexually transmitted infection, though Ghebreyesus said more needs to be learned if there are new modes of transmission through sexual activity. Ghebreyesus said it is possible that increased travel during the COVID-19 pandemic may have helped the virus spread.
Ghebreyesus was optimistic that it may be possible to control the spread "precisely because it remains primarily in one group, who as I said are very active in health-seeking behavior and supporting each other in reducing risk."
"We want to encourage that group to continue to undertake the actions both individually and collectively to reduce their own personal risk," he said.
In an effort to combat the spread of the disease, health officials are working to ramp up distribution of monkeypox vaccines.
Last week, HHS announced that it has ordered another 2.5 million doses of the JYNNEOS monkeypox vaccine, amidst increased demand for the shots. The department's latest order is in addition to its July 1 order of 2.5 million doses, which will begin arriving over the next year. The federal government expects to have an available supply of 7 million doses by mid-2023.
"I want to acknowledge that at this time the demand for vaccines from jurisdictions is higher than our current available supply, and we know that this is frustrating," Walensky said last week.
Teams are "actively working" to strategically increase supply to get the vaccines to "those who need it most," Walensky noted.
Dr. Ashish Jha, the White House's COVID-19 response coordinator, also acknowledged this week that the need for additional monkeypox vaccine doses is paramount.
"We got to keep going and we got to keep doing more," Jha added. "In the days and weeks ahead, you're gonna just see more and more."
ABC News' Somayeh Malekian contributed to this report.