Saudi Arabia has taken the unprecedented step of banning foreign pilgrims from entering the country five months before the annual hajj pilgrimages, while Japan will close its schools next week as countries around the world scramble to halt the spread of the coronavirus.

So far, the virus has killed nearly 3,000 people and infected more than 82,000, prompting warnings that the world is fast approaching a “tipping point”.

Saudi Arabia announced the ban late on Wednesday after more than 330 cases were confirmed around the Middle East, most of them in Iran. Authorities in Riyadh said the ban was temporary, but did not say how long it might last. The country has yet to report a case of the virus.

“The kingdom’s government has decided to [suspend] entry to the kingdom for the purpose of umrah and visit to the prophet’s mosque temporarily,” the Saudi foreign ministry said in a statement.

It said tourist visas would be suspended “for those coming from countries in which the spread of the new coronavirus is a danger” and urged Saudi citizens not to travel to countries where the disease was proliferating.

The umrah, which refers to the Islamic pilgrimage to Mecca that can be undertaken at any time of year, attracts millions of devout Muslims from all over the globe each year. There was no clarity over how the move would affect the annual hajj pilgrimage, due to start in late July.

About 2.5 million pilgrims travelled to Saudi Arabia from across the world to take part in last year’s hajj – one of the five pillars of Islam. The event is a key rite of passage for Muslims and a huge logistical challenge for Saudi authorities, with colossal crowds cramming into relatively small holy sites.

“This move by Saudi Arabia is unprecedented,” Ghanem Nuseibeh, the founder of the London-based risk consultancy Cornerstone Global Associates, told Agence France-Presse. “The concern for Saudi authorities would be Ramadan, which starts at the end of April, and hajj afterwards, should the coronavirus become a pandemic.”

On Thursday, Japan’s prime minister told schools across the country to close their doors from 2 March. The country has so far confirmed 178 cases of the virus.

“The government considers the health and safety of children above anything else,” said Shinzo Abe. “We request that all primary, junior high and high schools close temporarily from next week until their spring break.”

The spring break for public schools usually starts in late March in Japan and lasts several weeks.

Q&A How can I protect myself and others from the coronavirus outbreak? Show The World Health Organization is recommending that people take simple precautions to reduce exposure to and transmission of the coronavirus, for which there is no specific cure or vaccine. The UN agency advises people to: Frequently wash their hands with an alcohol-based hand rub or warm water and soap

Cover their mouth and nose with a flexed elbow or tissue when sneezing or coughing

Avoid close contact with anyone who has a fever or cough

Seek early medical help if they have a fever, cough and difficulty breathing, and share their travel history with healthcare providers

Advice about face masks varies. Wearing them while out and about may offer some protection against both spreading and catching the virus via coughs and sneezes, but it is not a cast-iron guarantee of protection Many countries are now enforcing or recommending curfews or lockdowns. Check with your local authorities for up-to-date information about the situation in your area. In the UK, NHS advice is that anyone with symptoms should stay at home for at least 7 days. If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home.

The latest drastic measures came as:

China’s health authority reported another drop in the number of new infections, with 433 new confirmed cases and 29 deaths in mainland China on Wednesday.

Iran’s state-run Irna news agency reported that the country had confirmed 245 cases and 26 deaths. Iran remains the regional hotspot for the coronavirus and is the country with the highest death toll outside China, where the Covid-19 outbreak originated. However, experts fear Iran is underreporting the number of cases.

Iraq announced the first confirmed case of coronavirus in the capital, Baghdad, taking nationwide infections to six and raising concerns about the capacity of the dilapidated health system to respond. Hours earlier, the government announced sweeping measures to try to contain the spread of the virus, ordering the closure of schools and universities, cafes, cinemas and other public spaces until 7 March.

The number of cases in Kuwait jumped from 26 to 43 – all linked to people who had recently visited Iran. Bahrain has reported 33 cases, the United Arab Emirates 13 and Oman four.

South Korea, which has the highest number of cases outside mainland China, reported a further 505 cases on Thursday, bringing its total to 1,766. It was the largest daily jump since the first confirmed infection on 20 January. Most of the cases were again centred on Daegu, where a church at the centre of the country’s outbreak is located.

Italy remained the centre of European infection, with 528 confirmed cases and 14 deaths.

A second person tested positive for the coronavirus in the eastern Spanish region of Valencia, bringing the total number of cases in the country to 15. The man – who is showing mild symptoms of the virus – was among the 2,500 Spaniards who travelled to Milan on 19 February to watch Valencia play Atalanta in the Champions League.

Denmark recorded its first case – a man returning after a skiing holiday in Italy – while Estonia, Pakistan, Brazil, Georgia, Norway, North Macedonia, Greece and Romania are among the countries that have reported their first cases of coronavirus in the past 24 hours.

As many countries took drastic measures and unveiled emergency plans, Donald Trump sought to downplay the threat posed by the virus.

In a press conference in Washington, the US president said the danger to Americans remained “very low” and predicted that the number of cases diagnosed in the country – currently at 15 – could fall to zero in a “few days”.

“We have had tremendous success, tremendous success, beyond what people would have thought,” he said, in remarks that appeared to be contradicted by officials from his administration at the same media briefing.

Dr Anne Schuchat, the principal deputy director of the Centers for Disease Control and Prevention (CDCP), appeared to reiterate her organisation’s warning from Tuesday that a greater spread in the US was inevitable.

“Our aggressive containment strategy here in the United States has been working and is responsible for the low levels of cases we have so far. However, we do expect more cases,” said Schuchat.

The US health secretary, Alex Azar, has requested $2.5bn (£1.9bn) in emergency funding from Congress to increase preparedness, but Democrat lawmakers said that was inadequate and have suggested an $8.5bn package.

A warning about the potential danger in the US came from the CDCP shortly after Trump finished speaking. It said that a person in northern California contracted the virus without travelling outside the US or having contact with a confirmed case.

Associated Press and AFP contributed to this report