Nearly 1,800 immigrant families were separated at the U.S.-Mexico border from October 2016 through February of this year, according to a senior government official, as President Donald Trump implemented stricter border enforcement policies.

The numbers are the first comprehensive disclosure by the administration of how many families have been affected by the policies. Previously, the only numbers provided by federal officials on family separations covered a single two-week period in May.

The government official, who agreed to speak only on condition of anonymity, said he could not provide up-to-date statistics, but acknowledged the number of separations had risen sharply in recent weeks, largely because of new administration policies.