GENEVA — Expressing alarm both about mounting infections and inadequate government responses, the World Health Organization declared Wednesday that the global coronavirus crisis is now a pandemic but added that it’s not too late for countries to act.

By reversing course and using the charged word “pandemic” that it had previously shied away from, the U.N. health agency sought to shock lethargic countries into pulling out all the stops.

“We have called every day for countries to take urgent and aggressive action. We have rung the alarm bell loud and clear,” said Tedros Adhanom Ghebreyesus, the WHO chief.

“All countries can still change the course of this pandemic. If countries detect, test, treat, isolate, trace and mobilize their people in the response,” he said. “We are deeply concerned by the alarming levels of spread and severity and by the alarming levels of inaction.”

The WHO said Iran and Italy are the new front lines of the battle against the virus that started in China.

“They’re suffering but I guarantee you other countries will be in that situation soon,” said Dr. Mike Ryan, the WHO’s emergencies chief.

He added that the agency thought long and hard about labeling the crisis a pandemic — meaning a new virus causing sustained outbreaks in multiple regions of the world.

The risk of employing the term, Ryan said, is “if people use it as an excuse to give up.”

But the benefit is “potentially of galvanizing the world to fight.”

Underscoring the mounting challenge: The case count outside China has multiplied 13-fold over the last two weeks to over 118,000, with the disease now responsible for nearly 4,291 deaths, WHO said.

“If you want to be blunt, Europe is the new China,” said Robert Redfield, the head of the U.S. Centers for Disease Control and Prevention.

Italy weighed imposing even tighter restrictions on daily life and announced billions in financial relief Wednesday to cushion economic shocks from the coronavirus.

For most, the coronavirus causes only mild or moderate symptoms, such as fever and cough. But for a few, especially older adults and people with existing health problems, it can cause more severe illnesses, including pneumonia.

But most people recover. People with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover, the WHO says.

In the U.S., the caseload passed 1,000, and outbreaks on both sides of the country stirred alarm.

At a Congressional hearing in Washington, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, sounded an alarm: “Bottom line, it’s going to get worse.”

“It’s terrifying,” said Silvana Gomez, a student at Harvard University, where undergraduates were told to leave campus by Sunday. “I’m definitely very scared right now about what the next couple days, the next couple weeks look like.”