WASHINGTON -- The Department of Defense says one of the four U.S. soldiers killed in an attack by extremists in Niger was a South Florida native.

The American soldier is 25-year-old Sgt. La David T. Johnson of Miami Gardens, Florida. Johnson was assigned to the 3rd Special Forces Group, based at Fort Bragg, North Carolina.

U.S. officials said they believe extremists linked to the Islamic State of Iraq and Syria (ISIS) were responsible for the attack about 120 miles north of Niamey, the capital of the landlocked nation in western Africa.

Sgt. La David Johnson U.S. Army Special Operations Command

The U.S. and Niger forces in a joint patrol were leaving a meeting with tribal leaders and were in trucks. They were ambushed by 40-50 militants in vehicles and on motorcycles.

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"The Bush Hog formation was made better because of Johnson's faithful service and we are focused on caring for the Johnson family during this difficult period," Lt. Col. David Painter said in a statement.

Johnson's neighbors said he was known around Miami as the "wheelie king."

"Every time you saw him he always had a full bicycle with just the handlebars," his neighbor Thomas Vinson told CBS Miami. "He would always take the front wheel off and ride around with it on the side. If he didn't have the front wheel he said he didn't need it -- ask him how far he could with it, he said he could go all over the world with it."

Johnson enlisted in the Army in January 2014 as a wheeled vehicle mechanic. His awards and decorations include the Army Achievement Medal, the Army Good Conduct Medal, the Global War on Terrorism Medal, the Army Service Ribbon, the Army Parachutist Badge, the Army Air Assault Badge, the Driver and Mechanic Badge and the Marksmanship Qualification Badge – Sharpshooter with Rifle, CBS Miami reports.

Three of the other U.S. troops killed were also identified Friday: Staff Sgt. Bryan Black, 35, of Puyallup, Washington, Staff Sgt. Jeremiah W. Johnson, 39, of Springboro, Ohio, and Staff Sgt. Dustin Wright, 29, of Lyons.

U.S. Africa Command said the U.S. forces are in Niger to provide training and security assistance to the Nigerien Armed Forces in their efforts against violent extremists.

Four Nigerien soldiers died in the attack and two other U.S. troops were wounded.