US Defense Secretary Jim Mattis warned Tuesday that an American withdrawal from Afghanistan would be "to our ultimate peril," as he briefed Congress on plans to increase US troop levels.
"Based on intelligence community analysis and my own evaluation, I am convinced we would absent ourselves from this region at our peril," he said, testifying before the Senate Armed Services Committee.
The administration of President Donald Trump recently announced plans to send an additional 3,000 troops to Afghanistan to train and advise the country's security forces. There are already 11,000 US troops there.
Mattis visited Afghanistan last week with NATO Secretary-General Jens Stoltenberg to reaffirm US commitment as government forces struggle to beat back the Taliban, which has been on the offensive since US-led combat forces withdrew at the end of 2014.
General John Nicholson, the top US commander in Afghanistan, "is holding the line," Mattis assured the senators.
"We must always remember we are in Afghanistan to make America safer and to ensure South Asia cannot be used to plot transnational attacks against the US homeland or our partners and allies," he said.
The September 11, 2001 attacks on the United States was set in motion from Taliban-ruled Afghanistan by Al-Qaeda leader Osama bin Laden.