Kenya is closing its borders to travellers from Guinea, Liberia and Sierra Leone, the three countries worst hit by the Ebola epidemic.
Kenya Airways also announced that it would suspend flights to the three countries, when the government travel bar on passengers comes into
Several European carriers have already suspended services to the Sierra Leonean and Liberian capitals.
States of emergency have been declared to try to slow the spread of the disease.
Kenyan Health Minister James Macharia said the measure is also aimed at travellers who have passed through the affected countries.
The measure does not affect health workers fighting the epidemic, Macharia said, nor Kenyans returning home from the three countries.
However, he warned that both groups would be subject to "strict checks... and it may be necessary to put people in quarantine".
Kenyan health officials have already spotted four suspected cases of Ebola, which experts say is raging out of control in west Africa, but all proved negative after tests.
Kenyan Airways will continue to fly to Nigeria, despite a much smaller Ebola outbreak in its largest city, Lagos, the company said in a statement.