An American has been killed fighting alongside Kurdish forces against ISIS in Syria, according to officials and relatives.
A State Department official confirmed to NBC News that American citizen Keith Broomfield was killed in Syria. The official did not provide further details, saying only that the State Department was in touch with Broomfield's family.
Broomfield, 36, was originally from Massachusetts.
Twitter accounts and Facebook pages linked to Kurdish fighters were first to report his death, calling Broomfield a "martyr" and saying he was killed in the Syrian countryside surrounding Kobani. There was no immediate official confirmation from the secular Kurdish forces fighting ISIS in Syria known known as the YPG.
Idris Nassan, Kurdish co-deputy foreign minister of the Kobani district, also confirmed to NBC News that an American who had joined Kurdish fighters died in a battle with ISIS in his area. It was not immediately clear when Broomfield was killed.
Broomfield's mother, Donna, said she had learned from her other son that Keith was dead.
"I didn't want him to go but I didn't have a choice in the matter," she tearfully told NBC News over the phone from Westminster, Massachusetts.
She said that her son had left to fight around four months ago and that while there was "a little bit of texting" after he first arrived, lately she had heard "nothing."
"I'm waiting for his body to come back," she added.
Numerous Americans are believed to have traveled overseas to join the Kurdish People's Protection Union, also known by the initials YPG, in their fight against ISIS. However, Broomfield is believed to be the first U.S. citizen to die fighting alongside the YPG.
News of Broomfield's death came as U.S. President Barack Obama authorized the deployment of 450 additional military personnel to help and advise Iraqi forces battling ISIS and attempting to push the Sunni militants out of the city of Ramadi.
In recent weeks, ISIS also has seized the Syrian city of Palmyra.
Cassandra Vinograd, Abigail Williams and Ammar Cheikh Omar contributed reporting.