Immigration desk computers at various US airports went down for about two hours on Monday, causing wait times for global travelers that were longer than normal, Customs and Border Protection said.
"U.S. Customs and Border Protection experienced a temporary outage with its processing systems at various airports today beginning at 7:30 p.m. EST and ending at approximately 9:30 p.m. EST".
Customs and Border Protection said its officers continued to process travelers using "alternative procedures" during the outage.
CBP also said it does not believe the outage was due to a malicious disruption.
Travelers entering the USA from overseas posted photos on social media of long lines at John F. Kennedy International Airport in NY and at Hartsfield-Jackson Atlanta International Airport.
Denver International Airport reported the "brief customs processing issue has been resolved".
"No one has been getting past JFK Airport immigration for the last hour".
A similar computer breakdown at United States airports happened a year ago.
Other affected airports included John F. Kennedy International Airport in New York, Dallas/Fort Worth International Airport and Miami International Airport, according to media reports and the airports' social media posts.