Defense Secretary Robert Gates wants to use the additional 1,400 Marines to secure gains NATO and Afghan forces have made, The Wall Street Journal reported. They would begin arriving well before the fighting season resumes with the spring.
Gates approved the deployment Wednesday. The United States is scheduled to begin reducing the size of its contingent in Afghanistan in July.
"The rationale is to take advantage of the gains we have made over the last several months and apply more pressure on the enemy at a time when he is already under the gun," Pentagon press secretary Geoff Morrell said.
In December 2009, when President Obama announced a temporary increase in troops in Afghanistan, he gave Gates the authority to add another 10 percent, or 3,000 soldiers, to deal with unexpected events. The additional battalion would exceed that number.