WASHINGTON — The US army has deployed an additional 180 tanks to Afghanistan, the first such deployment since the Pentagon launched airstrikes against the Islamic State of Iraq and Syria in Syria in September 2016.

The tanks, which were fitted with anti-tank guided weapons, are supposed to protect US special forces in the fight against the extremist group.

Defense Secretary Jim Mattis said the new deployment — which comes after the US Army lost 17 soldiers in the Moscow incident — followed two large-scale tests of their armored vehicles that showed good durability in harsh conditions.

“This is a big team,” he said at the Pentagon after meeting with US troops on Tuesday. “I like to have an idea when it’s going to get cold or when it gets warm, if it’s going to get fog, if it’s going to get rain, when it’s going to get rough.”

The return of the tanks comes as the US military is expected to support efforts by Russia to rein in the Islamic State of Iraq and Syria and an Al-Qaeda offshoot in Syria.

In March 2016, Russian aircraft spotted a line of US tanks lined up on the Syrian side of the border.

Following the incident, the Russian Defense Ministry refused to support any such US effort.

Mattis said he did not expect a change in Russian policy in Syria.

Russia launched its first airstrikes since 2015 in support of President Bashar Assad in September 2016.

Mattis called on Moscow to support his efforts to defeat the Islamic State.

“We need to do everything we can to defeat the terrorist organization,” he said.

“And if Russia can help us do that, then hopefully we will be able to have the same kind of cooperation.”