Deputy U.S. commander in Afghanistan Lt. Gen. David Rodriguez said Marines will be the first troops out of that country in the drawdown that' s to start this month. Rodriguez, who oversees the Afghanistan war's day to day operations, identified the first combat unit to be pulled back as the 3rd Battalion, 4th Marines deployed in Helmand Province. More than 800 Marines will begin withdrawing later this summer and into the fall, Rodriguez said via satellite to a Pentagon briefing. Apart from the Marines, about 300 troops from the Army National Guard's 1st Squadron, 134th Cavalry Regiment, and about 500 troops from the Guards's 1st Squadron, 113rd Cavalry Regiment in Parwan will not be replaced when they leave as scheduled in July, according to Pentagon officials. U.S. President Barack Obama has ordered the withdrawal of 10, 000 troops from Afghanistan by the end of this year to begin in July. Another 23,000 troops will be out of that country by next summer. Rodriguez said U.S. troops and their mission were put under " unnecessary risk" by the drawdown plan. "The decision has been made and now it's our turn to execute the decision. And we can do that without a significant change in risk." He said he is confident the United States "can draw down those troops through the end of this year and accomplish our mission."