However, Mattis did not provide details on when the White House would make an announcement or what the decision was on Afghanistan, where fighting still rages more than 15 years after U.S. forces invaded and overthrew a Taliban government.
Soon after taking office in January the Trump administration began a review of U.S. policy on Afghanistan, which has expanded into a broader South Asia review.
The ongoing war in Afghanistan started in 2001, following the US invasion of the country.
Many thought the US would slowly draw down troops and end the war once they killed 9-11 mastermind Osama bin Laden in 2011, but the US still has over 13,000 troops in Afghanistan and more in the region.
In February, the Trump administration said they were a few thousand troops shy of the necessary amount to take on the Taliban -- the Sunni insurgents who were removed from power in Afghanistan by US forces in 2001.
According to the Reuters article, a troop increase could come at levels slightly higher than earlier anticipated:
One U.S. official, speaking on the condition of anonymity, said Trump's top national security aides are backing adding between 3,000 and 5,000 troops and allowing them to embed with Afghan forces closer to combat.
However the administration decides to move forward, we expect Trump and Mattis to act with strength and decisiveness in Afghanistan.