He said he would chair an emergency Cobra meeting on the issue later.

It comes after the government’s chief scientist Sir Mark Walport warned Ebola was a threat because of how “interconnected” the world was now.

Public Health England has issued a national alert to all UK doctors amid fears the virus could spread.

Last week an infected Liberian man was found to have travelled through a major Nigerian airport.

Several West African airlines have now stopped flying to Liberia and Sierra Leone over concerns about the outbreak.

Spreading virus

Mr Hammond told BBC News: “At the moment we don’t think any British nationals [abroad] are affected and we are fairly confident there are no cases in the UK.

“But it is a threat, it is something we need to respond to and we will be doing so through the Cobra mechanism.”

Sir Mark 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.”

Elsewhere, Dr Brian McCloskey, director of global health at Public Health England, said the outbreak was “clearly not yet under control” in West Africa.

He told the Independent: “We have been talking to all levels of government, including the prime minister’s office, on the West Africa situation.

“When these things start to escalate we work with everybody to ensure they are aware of what needs to happen.”

BBC global health correspondent Tulip Mazumdar said the West African outbreak had been ongoing for four months.

In that time local people have been looking after the sick and carrying out burials which can actually help to spread the virus, she added, because it is spread by touching skin and contact with bodily fluids.

Ebola kills up to 90% of those infected, but patients have a better chance of survival if they receive early treatment.

The outbreak – the world’s deadliest to date – was first reported in Guinea in February. It then spread to Liberia and Sierra Leone.