There is an “increased likelihood” of cases of the new coronavirus occurring in the UK, Health Secretary Matt Hancock has said.
Globally, there are more than 500 confirmed cases of the virus, which has killed 17 people in China.
But there are no known cases in the UK, he said, which was “well prepared” to deal with an outbreak.
However, a small number of patients in Scottish hospitals are being tested after showing symptoms, it has emerged.
It is not yet known which hospitals are assessing the patients.
The new strain of coronavirus is believed to have originated in the Chinese city of Wuhan – and the city has gone into lockdown.
Authorities have suspended planes and trains in and out of the Chinese city – which has a population of 11 million people – as well as all public transport within Wuhan.
The UK is monitoring flights arriving from China as a precaution.
In a statement to the House of Commons, Mr Hancock said that it was a “rapidly developing situation and the number of deaths and the number of cases is likely to be higher than those that have been confirmed so far and I expect them to rise further”.
He told MPs: “The chief medical officer has revised the risk to the UK population from ‘very low’ to ‘low’ and has concluded that while there is an increased likelihood that cases may arise in this country, we are well prepared and well equipped to deal with them.”
He added: “The UK is one of the first countries to have developed a world-leading test for the new coronavirus.
“The NHS is ready to respond appropriately to any cases that emerge.”
In response to the outbreak, the Foreign Office has advised against all but essential travel to Wuhan.
On Wednesday, Public Health England began carrying out enhanced monitoring of direct flights from China.
Passengers are receiving advice on what to do if they fall ill, which Mr Hancock said was the most important part of the monitoring as it can take days after infection before a patient develops symptoms, so physical checks were considered less useful.
He added: “We are working closely with our counterparts in the devolved administrations and the public can be assured that the whole of the UK is always well prepared for these types of outbreaks.
“And we’ll remain vigilant and keep our response under constant review in the light of emerging scientific evidence.”
Authorities around the world have announced screening measures for passengers from China.
Singapore, Saudi Arabia and Vietnam are the latest countries to have registered a confirmed case.
Thailand has confirmed four cases of the virus – the most outside of China. The US, Japan, Taiwan and South Korea have all reported one case each.
The World Health Organization’s (WHO) emergency committee is meeting on Thursday in Geneva to decide whether or not to declare a “global emergency”.
A global emergency is the highest level of alarm the WHO can sound and has previously been used in response to swine flu, Zika virus and Ebola.
All the fatalities so far have been in Hubei province, of which Wuhan is the capital. Most of the 17 victims were elderly and suffered from other chronic diseases including Parkinson’s disease and diabetes.
The lockdown comes as millions of Chinese people travel across the country for the upcoming Lunar New Year holiday.
What do we know about the virus?
Currently known as 2019-nCoV, the virus is understood to be a new strain of coronavirus not previously identified in humans. The Sars (Severe Acute Respiratory Syndrome) virus that killed nearly 800 people globally in the early 2000s was also a coronavirus, as is the common cold.
Authorities have said it originated in a seafood market that “conducted illegal transactions of wild animals”. The market has been shut down since the beginning of the year.