The World Health Organization (WHO) is officially calling the coronavirus a pandemic.
"WHO has been assessing this outbreak around the clock and we are deeply concerned both by the alarming levels of spread and severity, and by the alarming levels of inaction," said WHO Director-General Tedros Adhanom Ghebreyesus.
"We have therefore made the assessment that Covid-19 can be characterized as a pandemic," he added.
Tedros said that in the past two weeks, the number of cases of coronavirus outside of China, where it originated, has increased 13-fold and the number of countries with cases has tripled.
There are now more than 118,000 cases in 114 countries, and 4,291 people have died, the WHO said.
Officials said at a news conference that the label "pandemic" does not automatically trigger any specific official actions, other than underscoring the seriousness and need to step up the fight even more.
"In the days and weeks ahead, we expect to see the number of Covid-19 cases, the number of deaths, and the number of affected countries climb even higher," Tedros said.
Officials in the United States also say they expect the number of cases to grow and are warning people to take steps to reduce the spread, such as canceling large gatherings, staying home when they feel ill and emphasizing proper hygienic procedures.
There are 1,050 confirmed cases of the coronavirus in the U.S., according to data compiled by Johns Hopkins University, with 29 deaths so far.
The WHO's move comes as Democrats in Washington are pushing for more action to help address the virus in the United States, with a particular focus on providing paid sick leave.
House Democrats are set to unveil their legislative package on Wednesday, with a vote expected the next day.
President Trump is pushing for more economic-focused measures such as a payroll tax cut, but has also expressed some openness to other ideas including paid sick leave.
There is pressure on the Trump administration to make testing more widely available, given a rocky start to ramping up testing that has been faulted for delaying the identification of cases and knowing how widespread the virus is in the U.S.
Washington, D.C.’s public health department on Wednesday recommended canceling gatherings of more than 1,000 people as a way to fight the virus.
With the coronavirus spreading in multiple areas of the U.S., experts say these "mitigation" measures are necessary to slow it and avoid overwhelming the health care system.
Experts are warning against mass gatherings and say that particularly vulnerable people, meaning those over 60 and with those with underlying health conditions, should especially avoid crowds, reconsider travel and stock up on supplies.