KABUL, Afghanistan — About 300 U.S. Marines will be sent to Afghanistan’s Helmand province to assist in intelligence and logistics matters Afghan security forces battling Taliban insurgents, the unit’s commander said over the weekend.

The deployment to Helmand will be the Marines’ first to the southern province since they left in 2014 as the U.S. declared an end to its combat mission. Since then, Afghan security forces, still backed by Washington in the form of airstrikes and hundreds of advisors, have struggled to contain the Taliban advance in Helmand.

Brig. Gen. Roger Turner told reporters on a conference call that the deployment would be part of a regular rotation to replace a U.S. Army unit already training and advising Afghan troops in the province. And although the 300 Marines would mostly be experienced and senior officers who will work on intelligence, logistics and administration, Turner said they were braced for a dangerous mission.

“We’re viewing this as a high-risk mission … We’re not in any way viewing this as a noncombat mission, or something to take lightly,” he said.

Tens of thousands of Marines fought fierce battles against the Taliban in Helmand over five years. Nearly 1,000 coalition troops have been killed there since the U.S.-led military intervention in 2001, more than in any other province.

In the last two years the Taliban have captured areas that were the site of some of the deadliest battles for the Marines, including Sangin, Marjah and Nowzad, and for much of 2016, they have threatened to take the provincial capital, Lashkar Gah.

In a statement posted online, Taliban officials ridiculed the Marines’ deployment as one of the “final failed efforts” by outgoing President Barack Obama to stem the violence in Afghanistan.

In recent months the U.S. military also has announced rotations of roughly 3,000 Army soldiers to Afghanistan, where about 8,400 American troops conduct advising missions and “counterterrorism” operations against groups like Islamic State and al-Qaida.

A small number of Marines are already in Afghanistan, including around 60 who help to secure the huge air base at Bagram.