Washington (CNN) US taxpayers will pay $72 million to deploy active duty troops to the southern border with Mexico in order to fulfill President Donald Trump's directive that the Pentagon reinforce border personnel readying for the arrival of Central American migrants.

The Pentagon said Tuesday the $72 million price tag covers the cost of deploying the approximately 5,900 active duty troops until December 15 and will increase the longer the troops are deployed.

Trump has said he will deploy as many as 15,000 troops if needed to push back against a group of migrants who are planning on asking for asylum . On Tuesday, Trump told reporters that the troops "are proud to be on the border. They are proud to be defending our nation. And we are not letting people in."

Pentagon spokesman Col. Rob Manning said in a statement that "based on the current phased force laydown of approximately 5,900 Active Component personnel through December 15, 2018, the estimated cost to deploy, operate, sustain, and redeploy forces is approximately $72 million."

Lawmakers briefed

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