WASHINGTON: US President Barack Obama on Friday named attorney Ron Klain to coordinate the US response to the Ebola outbreak, amid growing anxiety over its spread beyond West Africa.

Obama authorized the Pentagon to send reservists to take part in a US mission to combat the Ebola epidemic.

Western countries scrambled to review safety measures at airports and borders amid a mounting wave of fear that Ebola outbreak will spread worldwide.

The World Health Organisation (WHO) vowed to ramp up its efforts to help 15 African countries defend themselves against the virus, which has already killed around 4,500 people.

And EU health ministers, meeting in Brussels, agreed to coordinate measures at entry points to the 28-member Union, although any decision on screening for Ebola rests with individual European countries. A string of health workers have been evacuated back to Europe from Africa with Ebola, but the only confirmed case of transmission on the continent so far is a Spanish nurse in Madrid.

Doctors in Spain have identified six more cases of possible infection, including a missionary priest who recently returned from Liberia and has shown signs of fever.

And in France, a nurse who had earlier helped treat a returning Ebola patient was taken to a military hospital with what an official called a "suspect fever" — though initial tests for the virus came back negative.

In the United States, two nurses who treated a Liberian traveller have now fallen ill, to the embarrassment of health authorities, who faced questioning about how the disease had spread.

The first of them, Nina Pham, was transferred from Texas to the National Institutes of Health outside of Washington late Thursday. She wore a white protective suit as she stepped off a plane en route to one of the top US medical facilities. In a brief video taken earlier while she was in Texas, Pham looked lucid and smiling as she spoke to her doctor.

"I love you guys," an emotional Pham says, as she wipes away tears.

The vast majority of the cases have been in Liberia and its neighbours Sierra Leone and Guinea, which are also at the centre of WHO efforts to contain the disease. Eleven other African countries had also been singled out for special assistance.

"We need to make sure it doesn't spread to other countries," Isabelle Nuttall, head of the WHO's alert and response arm, told reporters in Geneva.