The Pentagon says it is reallocating $1.5 billion to help pay for construction of 80 miles of wall at the U.S.-Mexican border.

The money is being drawn from savings in numerous defense programs, including one that supports the Afghan army and other security forces.

The Pentagon in March had transferred $1 billion from Army personnel budget accounts to support wall construction.

The combined total of $2.5 billion is in response to President Donald Trump's declaration of a national emergency at the border. Trump vetoed Congress' attempt to reverse his emergency declaration.

The Pentagon also is expected to transfer up to $3.6 billion from military construction budgets to pay for wall construction. These plans have not yet been announced.