US airports have been thrown into chaos as new coronavirus health screening measures for people returning from Europe are brought into force.
Long queues formed as travellers waited for hours for the screenings before passing through customs.
Earlier, Vice-President Mike Pence said a ban imposed on travel from European nations would be extended to the UK and Ireland on Tuesday.
The US has more than 2,700 confirmed cases, with 54 deaths.
Illinois governor JB Pritzker said the long lines at Chicago's O'Hare airport were "unacceptable".
These crowds are waiting to get through customs which is under federal jurisdiction
— Governor JB Pritzker (@GovPritzker) March 15, 2020
End of Twitter post by @GovPritzker
People have been tweeting pictures and videos of passengers waiting to be processed, forming large crowds in airport terminals:
Passengers are being questioned about their medical histories and checked for symptoms.