LONDON, Aug. 28  -- The British Foreign and Commonwealth Office (FCO) on Thursday issued travel warnings to its nationals against "all but essential travel" to Sierra Leone, Guinea and Liberia due to the outbreak of Ebola.

"The UK advises against all but essential travel to Sierra Leone, Guinea and Liberia due to the ongoing Ebola outbreak and the impact this is having on commercial flights and medical facilities," the FCO said in its travel advice.

British Airways has suspended flights to Sierra Leone and Liberia until December 31 due to the deteriorating public health situation and some other airlines have also suspended flights to these countries, the alert said.

"If you are a British national in these countries, you should stay in contact with your employer or host organization about the support that they can provide to you while you are in the country or should you wish to leave," it added.

"You should be aware that the narrowing range of commercial flight options and growing restrictions on travel in the region may make it difficult to leave, particularly at short notice, and consider your own plans in this context," the FCO advised.

The Ebola virus spreads through bodily fluids with those infected. It has killed over 1,500 people this year in West Africa, mostly in Guinea, Liberia and Sierra Leone.