(CNN) The Pentagon announced Sunday approximately 3,750 additional U.S. forces will deploy to the southwest border to provide additional support to Customs and Border Protection.

That support includes a mobile surveillance capability through the end of September 2019 as well as placing 150 miles of concertina wire between ports of entry. The Defense Department said the total active duty forces supporting CBP at the border will be approximately 4,350.

These additional units are being deployed for 90 days.

On Thursday, CNN reported approximately 3,500 additional active duty troops will be deployed to the southern border to bolster security.

The Pentagon's decision to not reveal the size of the increase during a hearing before the House Armed Services Committee on Tuesday was slammed by the committee's chairman, Democratic Rep. Adam Smith of Washington.

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