The Pentagon will deploy dozens of additional U.S. military advisers to southern Afghanistan in coming weeks, a U.S. military official said, part of an effort to rebuild the Afghan army unit that has faced a bloody fight in Helmand province.

The advisers will be deployed to train the 215th Corps, the Afghan army unit based in Helmand, the official said. The poppy-rich province was once home to about 30,000 coalition troops and major operations run by U.S. Marines, but nearly all U.S. troops there withdrew by the end of 2014. In recent months pitched battles have been fought there, some of which involve U.S. Special Operations troops working alongside Afghanistan commandos.

The Taliban has seized territory in several parts of the province, and was said this week to be close to recapturing Sangin, a strategically important district that the Afghan military and Taliban have been fighting over for months.

The deployment of additional military advisers will come as the U.S. Army rotates in a conventional infantry battalion from the 10th Mountain Division to replace one that has been deployed for months in southern Afghanistan to provide security on and around bases there. That has led to some media reports that the United States will send hundreds of new soldiers to Helmand, but the total number of U.S. troops likely will increase by only a few dozen, a U.S. military official in Afghanistan said.

The Guardian reported Monday that hundreds of U.S. troops will arrive in Helmand province in coming weeks.

Col. Mike Lawhorn, a U.S. military spokesman in Kabul, told The Washington Post that the mission of the U.S. military will remain the same — to “train, advise and assist” Afghan forces in their fight against the Taliban. The total number of U.S. troops in Afghanistan will likely remain about 9,800, a military official said, while acknowledging that it might tick up slightly to account for the new advisers.

The shift in Helmand comes as the U.S. military prepares to swap in a new top commander in the country. Army Gen. John F. Campbell, the outgoing commander, is expected to be replaced within days by Army Gen. John “Mick” Nicholson. Nicholson testified recently that security in Afghanistan has deteriorated, and that he will “re-look at” what how many U.S. troops are needed in the country.

Nicholson also said he would consider a measure proposed by Campbell in which the U.S. military would unleash more airstrikes against not only al-Qaeda and the Islamic State, which it already has the legal authorities to do, but also against the Taliban.