The "new program of active monitoring of every person coming back to the country" from the West African nations in the midst of the world's largest Ebola epidemic was announced by the US Centers for Disease Control and Prevention.
Travelers concerned will be asked to carry out daily self-checks for fever and provide contact details of friends or family, said CDC director Tom Frieden.
The system aims to "further protect Americans against Ebola" by monitoring travelers for the entirety of the virus's 21-day incubation period.
Local and state health departments are to be closely involved in setting up the checks and follow-ups.
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Temperatures are recommended to be taken twice per day and reported once per day.
People traveling into the United States from these three West African countries will also receive a "care kit" that includes a tracking log, instructions for monitoring temperature, and pictorial description of symptoms, Frieden said.
There is also a phone number to call if symptoms develop and information on what to say over the phone.
"If you become sick, get care quickly because that could save your life and protect your family," said Frieden.