Defense Secretary Jim Mattis said Tuesday that the more than 3,000 additional troops being deployed to Afghanistan will effectively be on "combat duty" as they support Afghan security forces on the front lines.
"The fighting will continue to be carried out by our Afghan partners," he said, "but our advisers will accompany tactical units to advise and bring NATO fire support to bear when needed."
"Make no mistake, this is combat duty, but the Afghan forces will remain in the lead for the fighting," Mattis said at a Senate Armed Services Committee hearing on Afghanistan strategy that took place 16 years after U.S. troops went into Afghanistan in October 2001.
The commitment of U.S. troops to "combat duty" -- calling in airstrikes and providing direct tactical advice on the front lines -- marks a major shift from the Obama administration's strategy in ending U.S. troops' combat role in 2013.
Mattis was purposefully unclear on how many more U.S. troops would deploy to Afghanistan -- and when -- saying "more than 3,000" would bolster the 11,000 now on the ground "in the coming months," although senators on the committee said the number would be about 3,500.
"I'd like for you to tell me how the inclusion of 3,500 is going to change the battlefield equation," Sen. John McCain, the committee chairman, told Mattis.
When Sen. Kirsten Gillibrand, a New York Democrat, asked for a specific number, Mattis replied, "No, ma'am."
He said he would not give details "if it involves telling the enemy something that will help them."
Mattis said he would give the committee numbers in private sessions.
"I think the specifics are best shared with you alone," he said, adding he is open to asking President Donald Trump to authorize the deployment of more than 3,000 troops if he determines it is necessary.
"Right now, I think I have what I need," he said. "If not, I'll go back in" to ask Trump for additional troops.
On other issues, Mattis said he is in favor of the U.S. remaining in the Joint Comprehensive Plan of Action with allies to halt Iran's nuclear programs, despite Trump's criticism of the deal.
When asked by Sen. Angus King, an independent from Maine, whether he thinks the U.S. should continue to support the JCPOA, Mattis replied, "Yes, senator, I do."
-- Richard Sisk can be reached at Richard.Sisk@Military.com.