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Story highlights

CBP officials told McCaskill the cost could be lower in the future for less expensive barrier options

She also said the cost could go up

(CNN) —  

The top Democrat on the Senate homeland security committee has a question for the department: Could the President’s border wall cost nearly $70 billion?

Citing a Customs and Border Protection briefing for Senate offices on their border funding request in the budget, Missouri Sen. Claire McCaskill sent a letter Tuesday to the commissioner of CBP demanding more information on what a total border wall, as promised by President Donald Trump, would cost taxpayers.

According to McCaskill, the administration is asking for $2.6 billion in the 2018 budget for “less than 75 miles of new border barrier,” which comes out to $36.6 million per mile. That would put the cost for a more than 1,800-mile wall at upwards of $66.9 billion, she wrote.

While noting that CBP officials told her the cost could be lower in the future for less expensive barrier options, she also said the cost could go up.

“It is concerning that the cost of construction could also be significantly higher, as the cost of acquiring land currently owned by private individuals was not included in the estimate,” McCaskill said. “Regardless, the $36.6 million per mile figure is the only information, and the closest to a cost estimate that the committee has obtained from DHS.”

CNN was first to report on Monday that the 2017 budget request from the administration on the wall, $999 million, will fund 62 miles, 48 of which are new construction.