The UK has announced that schools will be closed from Friday as Italy announced a record daily death toll of 475.
There are now more than 200,000 cases of coronavirus globally and more than 8,000 people have lost their lives, according to a count maintained by Johns Hopkins University in the U.S.
The surge in deaths in Italy brings the number of dead in the country to 2,978, with almost 36,000 confirmed cases.
In the UK, Prime Minister Boris Johnson said that schools will close at the end of the day on Friday and not re-open until further notice.
Meanwhile, World Health Organization Director-General Tedros Adhanom called for solidarity in the fight against COVID-19.
"We know that mant countries now face escalating epidemics and are feeling overwhelmed. We hear you," he said.
"There is hope. There are many things that all countries can do [...] to help slow transmission of the virus," he said, including cancelling sporting events. But countries must continue to test, he added, or the virus could return once social distancing measures end.
Adhanom cited South Korea as an example of how to deal with the coronavirus, including testing, tracing victims and educating the public about the illness. He also cited the UAE, which provided planes that delivered medical supplies to Iran.
Iran on Wednesday reported its single biggest jump in fatalities from the coronavirus as another 147 people died, raising the country's overall death toll to 1,135.
The World Health Organization is giving a news conference now, which you can watch in the video player above.
The novel coronavirus emerged first in China, which for months had suffered the highest number of infections and deaths worldwide, but Europe is the new epicentre of the disease.
The head of China's coronavirus medical response team has called on Europe to take more proactive measures against the spread of COVID-19, warning "don't wait until it is too late".
At a glance: Key coronavirus developments
Iran says another 147 people have died, pushing death toll there to 1,135 in the biggest 24-hour rise yet. Iranian state TV warns ``"millions" could die if the public ignores health guidance.
The first death from the virus in sub-Saharan Africa has been announced by an official in Burkina Faso
The UK confirms a surge in cases. Schools, restaurants and bars remain open.
Wuhan, the central Chinese city where the virus was first detected, reports just one new case on Tuesday.
EU leaders have agreed to prevent foreigners from entering the European bloc for 30 days, and a number of countries have instigated draconian measures such as nationwide lockdowns to stem the spread of the virus which has killed almost 8,000 people to date.
But Zhong Nanshan, the head of China's appointed medical team of experts, said while some countries are carrying out confinements, "people go out for a coffee, they meet ... This is not how this type of quarantine works." He recommended more proactive measures to identify infections more quickly and to be more effective in putting restrictions and quarantines into action.
In north America, US President Donald Trump announced the temporary closure of the US-Canada border "by mutual consent".
Major music events have started announcing postponements and cancellations, with Eurovision and Glastonbury both cancelling for this year.
EU closes borders
Late on Tuesday European Commission President Ursula von der Leyen said the proposal to block travel “got a lot of support by the member states. It’s up to them now to implement. They said they will immediately do that."
At a press briefing on Tuesday night, Hans Henri P. Kluge, the World Health Organization's regional director for Europe, said that 152 countries were now affected by COVID-19, creating a "new reality" for millions of people across the world.
"Europe is the epicenter of the first pandemic of coronavirus and every country, with no exceptions, need to take their boldest actions to stop or slow down the virus spread. Boldest action should include community action. Thinking that “this does not concern me” is not an option," he said.
Italy now has nearly a third of the world's deaths from coronavirus as Rome announced 345 more fatalities on Tuesday, taking the countries death toll to more than 2,500.
Global deaths from the outbreak - the epicentre of which has moved from China to Europe - are around 7,800.
Italy's civil protection agency said there had been a further 3,500 new infections and that intensive care beds were full in Bergamo, a city in the worst-hit region of Lombardy.
Italy, which has the world's second-oldest population after Japan, has been blindsided by a virus that appears to be deadlier for the elderly. The entire country remains on a strict lockdown, but it has so far failed to stem the flow of new infections.
France began its own lockdown on Tuesday, joining its neighbour Spain.
The UK has urged Britons to socially distance and stay away from bars, clubs and restaurants. But, unlike some other European countries, they remain open, as do schools.
Authorities there said of the 56,221 people who have been tested, 2,626 were positive for COVID-19, as of Wednesday morning.
The UK's health service said all "non-urgent elective surgery" would be suspended to increase capacity in hospitals for coronavirus infections.
In a speech to the nation on St Patrick's Day on Tuesday night, Irish Taoiseach Leo Varadkar warned that the current climate was "the calm before the storm, before the surge" and that he expected the restrictions on movement in Ireland last as long as the summer of 2020.
"Many of you want to know when this will be over; the truth is, we just don't know yet," he said.
The race for a vaccine
Tests on an experimental vaccine to protect against the new coronavirus have begun in the United States, the first of many efforts around the world to create a vaccine as cases continue to grow. But experts warn it could take a year to 18 months to approve it.
Forty-five healthy adults between the ages of 18 and 55 will participate in the trial over six weeks. The first participant in the study received a dose on Monday.
The US National Institutes of Health is funding the trial, taking place at the Kaiser Permanente Washington Health Research Institute in Seattle.
In Europe, the EU announced a large investment in a German company, CureVac, which is working on a vaccine. The investment follows reports the US was looking to buy the company.
Helge Braun, Angela Merkel’s chief of staff, told the German newspaper Bild that officials had “very intensive contact” with CureVac “when there were thoughts of enticing it to the United States”.
“I am proud that we have leading companies like CureVac in the EU,'' said European Commission President Ursula von der Leyen, Germany's former defense minister, on Monday. “Their home is here, but their vaccines will benefit everyone, in Europe and beyond.”
The Commission said it will provide up to €80 million in support.
Effects of confinement appear to show some progress in Italy
Researchers at Oxford said that there were already seeing the effects of the lockdown in Lodi, which was enacted in late February.
They say that the strict lockdown in Lodi appears to show a flattening of the curve of the epidemic.
Flattening the curve is a term that is being employed to show that measures such as confinement and social distancing can delay the peak of an epidemic. This means fewer people are in intensive care units in hospitals, which will help to slow the burden on health care systems.
"While cases in the province of Bergamo began to increase from Feb 24th, in contrast to Lodi no shutdowns or restrictions were imposed," the Oxford sociologists note in a study on how demographics can affect the epidemic.
The entire province of Lombardy was instead shut down roughly two weeks later on March 8.