Two patients in England, who are members of the same family, have tested positive for coronavirus, Chief Medical Officer for England Professor Chris Whitty said.
The first cases of the virus to be diagnosed in the UK were announced as more than 80 Britons on an evacuation flight from the Chinese city at the centre of the outbreak were due to land in the UK.
The Department of Health declined to say where in England the patients were from but it is understood they are not in the Wirral area, where a special facility has been set up to quarantine those returning from Wuhan.
In a statement, chief medical officer Professor Chris Whitty said: "The patients are receiving specialist NHS care, and we are using tried and tested infection control procedures to prevent further spread of the virus.
"The NHS is extremely well-prepared and used to managing infections and we are already working rapidly to identify any contacts the patients had, to prevent further spread.
"We have been preparing for UK cases of novel coronavirus and we have robust infection control measures in place to respond immediately.
"We are continuing to work closely with the World Health Organisation and the international community as the outbreak in China develops to ensure we are ready for all eventualities."
It comes as Virgin Atlantic has suspended its flights between Britain and China due to fears about the spread of the coronavirus.
The airline said in a statement it would suspend its daily operations between the UK and Shanghai for two weeks from Saturday.
The decision came after the World Health Organisation on Thursday declared the coronavirus outbreak an international public health emergency.
It also follows British Airways' decision to suspend flights to and from China, which is in place until at least Monday.
An aircraft carrying 110 passengers, including 83 Britons, has left Wuhan for the UK following the coronavirus outbreak in the Chinese city, the Foreign and Commonwealth Office (FCO) has said.
The plane, chartered by the FCO, is expected to land at the Brize Norton RAF base in Oxfordshire at 1pm.
It is understood the British passengers will be taken to an NHS facility on the Wirral to be quarantined for 14 days.
"It's welcome news that our evacuation flight has now left Wuhan," Foreign Secretary Dominic Raab said in a statement.
"We know how distressing the situation has been for those waiting to leave. We have been working round the clock to clear the way for a safe departure. The welfare of those trapped and public safety have been our overriding priorities."
After landing at Brize Norton, the chartered aircraft will continue to Spain, where the 27 non-British nationals on board will be processed by their EU home governments, the FCO said.
The Foreign Office has said the flight carrying Britons back from Wuhan is now expected to land half an hour later.
It tweeted: "Update: civilian aircraft chartered by the Foreign Office carrying 83 British and 27 foreign nationals is expected to land at RAF Brize Norton at 1330."
More follows
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here