"Secretary Mattis has made no decisions on a troop increase for Afghanistan. As he said throughout the week in testimony, the revised Afghanistan strategy will be presented to the President (Donald Trump) for his approval in the coming weeks," Pentagon spokesperson Dana W White said.
"The president has delegated force management authority for Afghanistan to the secretary. The secretary will continue to follow the president's guidance on our overall strategy.
The White House said such an authorisation to Mattis is part of the broader plan.
"The president is simply giving the secretary of defence -- this is one piece of a broader cohesive plan for that region -- and he wants to give secretary Mattis the ability to manage the troops and the resources to do so," White House Deputy Press Secretary Sarah Sanders told reporters at her daily news conference yesterday.
Yesterday, media reports claimed that Mattis was authorised by Trump to "manage" US troop levels in Afghanistan, paving the way for sending more American forces amidst a surge in Taliban attacks in the war-ravaged country.