Nine people in the UK are awaiting test results for coronavirus, as the medical director of Public Health England (PHE) said it was "highly likely" cases would be seen in Britain.
Professor Paul Cosford, emeritus medical director at PHE, said it is still "early days" in the course of the virus, but stressed that most of those affected abroad are making a good recovery.
But he said it was "highly likely" that cases would be seen in the UK.
So far, 14 people in the UK have been tested for coronavirus, with five given the all-clear and nine still awaiting results.
The Scottish Government confirmed on Thursday that five people were being tested after presenting with symptoms of the illness, while it was understood that another patient was tested at Belfast's Royal Victoria Hospital.
Two of those being tested in Scotland had been diagnosed with flu after travelling to Wuhan in China – the origin of the global outbreak.
— Public Health England (@PHE_uk) January 23, 2020
Downing Street said four out of five suspected cases in Scotland were believed to involve Chinese nationals.
Meanwhile, the official death toll in China has risen to 26 with more than 830 confirmed cases.
Speaking on the BBC Radio 4 Today programme, Professor Cosford said: "I think it's highly likely that we will have cases in the UK."
Speaking on BBC Breakfast, he said anyone who has travelled to Wuhan in the last two weeks and returned to the UK, and who has symptoms, must get in touch with the NHS.
Symptoms of coronavirus include fever, sneezing and coughing.
Professor Cosford said: "We will not be surprised if people return from China to the UK with the infection, the important thing is that if you are one of those people and you develop symptoms you get in touch quickly.
"We are testing anybody who meets the criteria. The numbers aren't the important thing, the important thing is that anybody who has been to Wuhan in the last 14 days and has symptoms, respiratory symptoms that could represent this virus... that we ask them to phone NHS 111 and then we can arrange any appropriate testing."
He said there was no precise figure for how many people have been in contact with the NHS who may have symptoms.
He added: "It's important that while you do make contact with us, that you keep yourself away from too many other people, because of course if you have been infected, it's important that we prevent spread.
"All our GPs and hospitals across the country have had a letter from the chief medical officer and the medical director at NHS England and us at Public Health England, so that if somebody does present and they are worried, if they do meet our criteria, that they will be put somewhere where they won't infect other people while they're assessed and while we can get them tested."
Asked if face masks could provide protection, Professor Cosford said PHE was not advising people to use face masks at the moment, but is monitoring developments carefully.
He said: "These are early days with this virus, the vast majority of people who are infected do seem to be getting better.
"The people who have sadly died do seem to have other conditions that might make them more likely to suffer badly with this virus."
In a statement to the Commons on Thursday, Health Secretary Matt Hancock said while "there is an increased likelihood that cases may arise in this country, we are well prepared and well equipped to deal with them".
Also on Thursday, the World Health Organisation (WHO) said it is "too early" to declare an international public health emergency over the outbreak "given its restrictive and binary nature".
Speaking at a press conference, Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: "Make no mistake, this is though an emergency in China.
"But it has not yet become a global health emergency.
"It may yet become one."
Other cases have been reported in Japan, South Korea, Singapore, Thailand, the US and Vietnam.
Dr Tedros said: "We know that most of those who have died had underlying health conditions such as hypertension, diabetes or cardiovascular disease, that weakened their immune systems.
"We know that there is human-to-human transmission in China, but for now it appears limited to family groups and health workers caring for infected patients.
"At this time, there is no evidence of human-to-human transmission outside China, but that doesn't mean it won't happen."
Wuhan – which has a population of 11 million people – has gone into lockdown, with authorities suspending planes and trains in and out of the city.
Beijing, Hong Kong and Macau have also cancelled some events to stop large crowds gathering together, as the country prepares to celebrate the Lunar New Year.
The UK is monitoring direct flights arriving into the UK from China as a precaution.
Passengers are receiving leaflets and advice on what to do if they develop symptoms, and a PHE health team is on standby at Heathrow.