The World Health Organization on Wednesday, March 11, declared coronavirus a pandemic, signaling that health experts believe efforts should be focused less on containing the virus and more on stockpiling materials, getting hospitals ready to handle an influx of patients and enacting social distancing policies.

"We are deeply concerned both by the alarming levels of spread and severity and by the alarming levels of inaction," WHO Director-General Ted ros Adhanom Ghebreyesus said.

The declaration came as the number of novel coronavirus cases surpassed 120,000 worldwide. In the United States, where more than 30 people have been killed by the coronavirus, the total number of cases has doubled in a matter of days, surpassing 1,000 late Tuesday.

The WHO's announcement does not trigger any new funding, protocols or regulations. But it is an acknowledgment of reality.

For weeks now, the WHO has hesitated to make the declaration because there is little upside, and it could create widespread panic. "It may cause fear," Tedros said at a briefing earlier this month.

But Wednesday, Tedros noted the scale of the outbreak. "There are now more than 118,000 cases in 114 countries, and 4,291 people have lost their lives," he said.

"In the days and weeks ahead, we expect to see the number of coronavirus cases, the number of deaths and the number of affected countries to climb even higher."

Tedros cautioned that "pandemic" is not a word to be used lightly or carelessly - that if misused, it can cause unreasonable fear or spur resignation that the fight is over, leading to unnecessary suffering and death. But he said he decided to use it because some countries did not act with enough speed or diligence.

In the past, health experts have used "pandemic" as a signal that efforts to contain an outbreak have failed and that countries should focus their efforts more on mitigating its effects through actions such as getting hospitals ready to handle an influx of patients, stockpiling materials and enacting social-distancing policies.

This outbreak has behaved differently, however, and the WHO has stressed in recent weeks that some countries should focus on containment even as they begin ramping up mitigation efforts.

By working to contain the virus, countries with only a few cases can slow down the spread and buy time to work more on mitigation strategies, Tedros said.

The worst is yet to come with the coronavirus outbreak in the United States, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said.

Fauci told lawmakers at a congressional hearing on the Trump administration's response to the spreading virus that with enough cases of community spread, where the origin is unclear, the situation becomes one "where you're not going to be able to effectively and efficiently contain it."

"The blended and comprehended approach should continue … it would be a mistake to abandon the containment strategy," he said. "We have never before seen a pandemic sparked by a coronavirus. And we have never before seen a pandemic that can be controlled at the same time."

U.S. markets slid as coronavirus tightened its grip on the economy and the oil price war escalated. The Dow was off more than 1,200 points Wednesday afternoon.

House Democrats plan to vote Thursday on a wide-ranging coronavirus relief package that will include expanded unemployment insurance, paid sick leave and food security assistance. But the effort shows how political leaders are moving in much different directions in their rushed attempts to contain the economic turmoil caused by the coronavirus outbreak.

President Donald Trump is pushing aides to develop a large tax cut package, and he could allow people to delay filing their taxes. The Senate, meanwhile, is moving more slowly and is not expected to act before a congressional recess scheduled for next week.

In other developments:

- German Chancellor Angela Merkel warned Wednesday that up to 70% of her country could end up infected.

-- In Italy, there are now more than 10,000 coronavirus cases. Schools and universities across Poland, as well as in the Ukrainian capital, Kyiv, will be shut for the rest of March, as European countries attempt to limit large gatherings.

- South Korea's daily tally of new confirmed cases, which had been declining amid a mass testing program, almost doubled the previous day's numbers.

- Iran announced 63 more coronavirus deaths, bringing the death toll to over 350. With another thousand infections announced, the country's total has increased to more than 9,000.

- Washington state will prohibit gatherings of more than 250 people in the Seattle area, one of the most drastic moves yet to contain the spread of the coronavirus at the site of its worst outbreak.

- District of Columbia Health Department officials are recommending that "nonessential mass gatherings, including conferences and conventions," be postponed or canceled in the nation's capital. The recommendation is in effect through March 31.

This article was written by Rick Noack, Lateshia Beachum, Alex Horton and Miriam Berger, reporters for The Washington Post.