BBC:
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 European nations over the pandemic 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“.