The service in a press release on Wednesday said the deployment of troops from 3rd Cavalry Regiment, 1st Cavalry Division, is part of a regular rotation of forces in support of Operation Freedom's Sentinel.
Maj. Gen. John Thomson, the division commander, said in the release, "The troopers of the regiment are well-trained, well-equipped, and most importantly well-led. They are absolutely ready for this important mission."
The soldiers are expected to switch out with a number of U.S. troops in Afghanistan and aren't likely to change the overall American military presence in the country of about 9,800 service members.
Lt. Col. Sunset Belinsky, a spokeswoman for the division, said the regiment will probably deploy in May or June. Soldiers are currently returning from the National Training Center at Fort Irwin, California, and will take a week or two of family leave before heading overseas, she said.
Belinsky said at least some of the soldiers may join colleagues from the 10th Mountain Division in the southern part of the country, but added that planners were still "looking at the mission closely, so it may not be exactly there."
The Defense Department announced in February that about 500 soldiers from 2nd Battalion, 87th Regiment, 10th Mountain Division, based at Fort Drum, New York, would be sent to Helmand Province to shore up an Afghan Army Corps battered by the Taliban.
In recent weeks, American F-16 fighter jets have "significantly increased pressure and the number of strikes" in eastern Nangarhar province bordering Pakistan, where fighters pledging allegiance to the Islamic State of Iraq and Syria, or ISIS, were believed to number 1,000-3,000, according to Army Brig. Gen. Wilson Shoffner, chief spokesman for U.S. Forces-Afghanistan.
President Barack Obama last year adjusted plans for U.S. troop levels in Afghanistan.
Rather than reduce the military footprint in the country to a nominal embassy presence in Kabul by the end of 2016, Obama said the U.S. will maintain 5,500 troops and a small number of bases, including at Bagram and Jalalabad in the east and Kandahar in the south into 2017 to continue the mission of training and providing support to Afghan security forces, according to the Pentagon.
Note: This story has been updated with a more accurate number of deploying troops in the first paragraph and with quotes from an Army spokeswoman beginning in the fifth paragraph.
-- Richard Sisk contributed to this report.