The People Protection Units or "YPG" are the main armed service of the Federation of Northern Syria – Rojava, and consist primarily of Syrian Kurds. The Turkish government consider the YPG to be part of the PKK, which they classify as a terrorist organization.
This 2015 Bloomberg article reports that US supplied weapons to YPG fighters, while claiming to have provided them to "Syrian Arabs fighting the Islamic State", instead.
Last weekend, the White House announced that the U.S. had dropped 50 tons of ammunition to Syrian Arabs fighting the Islamic State. Some officials now say that the new Arab coalition was a front and that Kurdish groups received most of the weapons -- as the U.S. intended.
American and Kurdish officials and Syrian Arab opposition leaders told us this week that ammunition said to have been for the Syrian Arab Coalition, a newly announced group of Sunni Arab brigades in northeastern Syria, had largely ended up arming the Kurdish Democratic Union Party and its associated military forces, known as the People's Protection Units or YPG. That will aid the Kurds in fighting the Islamic State and cementing their control of Kurdish territory.
In other words, US used the Arab fighters as a front to arm the YPG which is designated as a terrorist organization by Turkey. Is this claim true?