The British government views Ebola as a "very serious threat", Philip Hammond said today, as it emerged that man has been tested at a hospital in Birmingham suspected of carrying the deadly virus into the UK, after travelling from Nigeria via Paris.
The unidentified man has since tested negative for the virus, the Daily Mail reported, but health professionals are being urged to keep vigilant for signs of the deadly ebola virus amid fears that it could spread to the UK.
Another man visited Charing Cross Hospital in west London over fears he had the virus, but doctors ruled out the need for an Ebola test.
Public Health England has briefed border officials and airport staff on the symptoms and issued an urgent warning to doctors after an infected man was able to make multiple flights from Liberia to Nigeria, where he died.
Hammond said no British national so far had been affected by the outbreak but added he would be chairing the Government's Cobra emergencies committee later today.
"As far as we are aware, there are no British nationals so far affected by this outbreak and certainly no cases in the UK. However the Prime Minister does regard it as a very serious threat and I will be chairing a Cobra meeting later today to assess the situation and look at any measures that we need to take either in the UK, or in our diplomatic posts abroad in order to manage the threat," he told Sky News.
"We are very much focused on it as a new and emerging threat which we need to deal with."
The latest outbreak is the largest in history and has killed more than 670 people in the west African countries of Sierra Leone, Liberia, Guinea and Nigeria, including a doctor who was treating patients.
The disease can have a fatality rate of up to 90%, and there is no treatment or vaccine.
Dr Brian McCloskey, director of global health at Public Health England, said the outbreak was "clearly not yet under control", describing it as the most "acute health emergency" facing Britain.
McCloskey said later in a statement issued by PHE that the body was continuing to closely monitor the outbreak in West Africa.
"It's clear the outbreak is not under control," he said. "The risk to UK travellers and people working in these countries of contracting Ebola is very low, but we have alerted UK medical practitioners about the situation in West Africa and requested they remain vigilant for unexplained illness in those who have visited the affected area.
"People who have returned from affected areas who have a sudden onset of symptoms such as fever, headache, sore throat and general malaise within three weeks of their return should immediately seek medical assistance - but it is important to stress that no cases of imported Ebola have ever been reported in the UK and the risk of a traveller going to West Africa and contracting Ebola remains very low, since Ebola is transmitted by direct contact with the blood or bodily fluids of an infected person."
Sir Mark Walport, the Government's chief scientific adviser, said the disease was "potentially a major threat" to Britain because the increasingly "interconnected" nature of the world meant disruptions in far-off countries can have a major impact.
He told the Daily Telegraph: "The most dangerous infections of humans have always been those which have emerged from other species. They are a potential major threat to us. Emerging infectious disease is a global grand challenge.
"We were lucky with Sars. But we have to do the best horizon scanning. We have to think about risk and managing risk appropriately."
Health workers tackling the outbreak in the region have been especially vulnerable to contacting the disease.
Dr Sheik Humarr Khan, who was treating patients with ebola in Sierra Leone, died yesterday after being quarantined in hospital in the country.
Two American health workers - a doctor and a missionary - are also in hospital in neighbouring Liberia after contracting the disease, prompting two US missionary groups to evacuate non-essential personnel from the country.
The major regional airline ASKY has suspended flights to Monrovia, the capital of Liberia, and Freetown in Sierra Leone, following the death of 40-year-old American Patrick Sawyer, who was of Liberian descent, after he took several of its flights. His sister had also died of ebola.
Sawyer died in the Nigerian city of Lagos, Africa's largest, which is far better connected to the outside world than the rural areas of Sierra Leone, Liberia and Guinea where the outbreak has been raging since March, killing around 670 people so far.
He collapsed on arrival at Lagos' airport and died in hospital. It is understood his flight had stopped over in Liberia.
Though air passengers are now being screened in the three affected countries, the virus incubates for between two and 21 days before the person shows any symptoms and the virus cannot always be detected in those newly infected.
Public Health England (PHE) told The Huffington Post UK that Sawyer's death was "a cause for concern" as it showed the disease had moved from one country to the other.
According the World Health Organisation, ebola is one of the world's most virulent diseases.
Infection comes from direct contact with the blood, body fluids and tissues of infected animals or people, and those most at risk of infection are health workers, family members and others in close contact with the sick and dead patients.
Infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.
Ebola is a severe acute viral illness, and symptoms include the sudden onset of fever, intense weakness, muscle pain, headache and a sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.
It can take up to 21 days for symptoms to show after being infected. The disease has killed around 60% of those it has infected in the latest outbreak. In previous outbreaks, it has killed up to 90% of those infected.
Professor David Heymann, head of the Centre on Global Health Security at Chatham House in London, said it was difficult to stop infected people travelling around the world if their symptoms are hidden.
He told the Telegraph: "The best thing would be if people did not travel when they were sick, but the problem is people won't say when they are sick."