Britons have been advised by the Foreign Office against all but essential travel to Malta, due to travel restrictions implemented by the Maltese government related to the coronavirus (COVID-19) pandemic.
Malta on Thursday imposed a 14-day mandatory quarantine period on arrivals from all countries.
Asymptomatic visitors can choose to either enter mandatory self-quarantine or return to their country of origin as soon as possible.
"If you choose to leave Malta you must travel directly from your accommodation to the airport where you will be thermally screened. Most flights continue to operate but this could change at short notice," the Foreign Office said.
Meanwhile, UK media has reported that British Prime Minister Boris Johnson is preparing to follow other European countries in banning mass gatherings after the country registered a jump in its number of coronavirus cases and deaths.
Johnson, who has faced criticism for his country's light-touch approach to tackling the outbreak, is expected to introduce emergency legislation next week with the ban coming into force from next weekend.
Britain's death toll from the disease nearly doubled on Saturday, as health officials announced 10 more people had died, bringing the total number of fatalities to 21.
Official figures released Saturday showed the country has 1,140 confirmed cases -- an increase of 342 from the day before.
But a senior health official has estimated that the number of infected people is more likely to be between 5,000 and 10,000.
The government's new legislation could see the cancellation of events such as the Wimbledon tennis tournament and the Glastonbury music festival, due to begin at the end of June, as well as major horse races including Royal Ascot and Grand National.
Its current plan is to try to delay the peak of the outbreak until the weather becomes warmer to cushion the blow on the health services, and the advice so far is for people who show symptoms to self-isolate for a week.
The government has said the ultimate hope is that the country develops "herd immunity" to the virus, but World Health Organisation (WHO) spokeswoman Margaret Harris on Saturday warned that not enough was known about the COVID-19 to justify such an approach.
"We don't know enough about the science of this virus, it hasn't been in our population for long enough for us to know what it does in immunological terms," Harris told BBC Radio 4.
"We can talk theories, but at the moment we are really facing a situation where we have got to look at action."
However, health officials advising the government argue that taking drastic measures too early would have only limited benefit and would risk tiring a population before the peak of the crisis.
US extends travel ban to the UK
US Vice President Mike Pence announced Saturday that a travel ban imposed on European nations over the coronavirus pandemic would be extended to the United Kingdom and Ireland starting at 4am Tuesday.
"Americans in the UK or Ireland can come home. Legal residents can come home," Pence told a White House news conference, adding that such people would be "funnelled through specific airports and processed."
A 30-day US ban on travel from the EU's Schengen border-free zone took effect on Saturday, but notably excluded Britain and Ireland.
Trump had earlier confirmed the ban would be extended to those countries as the pandemic progressed, saying: "They've had a little bit of activity, unfortunately."
Cancellations
Many events such as Premier League football matches, the London Marathon and the May local elections have already been suspended or postponed.
Queen Elizabeth II has postponed a number of engagements scheduled for next week "as a precautionary measure", according to Buckingham Palace.
Her eldest son, Prince Charles, has postponed a trip to Bosnia, Cyprus and Jordan, scheduled to begin next week.
Johnson has come under increasing pressure to follow fellow European leaders in cancelling large gatherings, but he has previously said the government would only do so when health officials advised him to.
Health experts on Saturday demanded that their colleagues advising the government "urgently and openly share the scientific evidence, data and models it is using to inform its decisions."
"This transparency is essential to retain the scientific community, healthcare community, and the public's understanding, cooperation and trust," they wrote in a letter to The Times.