A report by the Department of Homeland Security finds that more than 600,000 foreigners who came into the United States legally in 2016 overstayed their visas and never left at the end of the year, USA Today reported.
Those who overstayed only represent 1.25 percent of the 50 million who came to the U.S. in 2016 via the nation's airports and seaports.
However, they are an estimated 40 percent of the 11 million undocumented immigrants who do live in the United States.
"Identifying overstays is important for national security, public safety, immigration enforcement, and processing applications for immigration benefits," the DHS report said.
The DHS says that it provides daily information on those who overstayed their visas to Immigration and Customs Enforcement, which is the agency responsible for enforcing immigration laws inside of the country.