"On the number of troops, no, I have not made a recommendation yet," said Mattis here at a Pentagon briefing. "That recommendation is being put together by the chairman (of the U.S. Joint Chiefs of Staff Joseph Dunford) and myself, and I expect it'll go to decision very very soon."
U.S. media reported earlier this month that U.S. President Donald Trump was close to decide on whether to send hundreds of additional U.S. troops to Afghanistan.
National Security Adviser H.R. McMaster said on May 12 that Trump would discuss the issue with allies at the North Atlantic Treaty Organization summit in Brussels and Group 7 meeting in Italy later this month.
Former U.S. President Barack Obama had planned to reduce the current number of 9,800 U.S. troops in Afghanistan to some 5,500 by the end of 2015 and withdraw all troops by the end of 2016 when his presidency came to an end.
However, given the deteriorating security situation in Afghanistan, the Obama administration repeatedly postponed the withdrawal.
U.S. National Intelligence Director Dan Coats warned earlier this month that the situation in Afghanistan would most likely deteriorate in the future even if the United States and its allies offer more military aid.
Currently, there are about 8,400 U.S. troops and another 5,000 NATO forces in Afghanistan to train and assist Afghan forces against the Taliban and conduct counter-terrorism missions.