"The aircraft delivered items that were provided by Kurdish authorities in Iraq and intended to enable continued resistance against IS' attempts to overtake Kobane," the Pentagon said Sunday.
The move was partly humanitarian but also aimed at shoring up the Kurdish defenders of Kobane, CNN quoted senior US officials as saying.
"This is a part of President Barack Obama's larger strategy to degrade and destroy IS wherever they are," an official said.
The gear was delivered by three C-130 cargo planes and appeared to have been received on the ground by Kurdish fighters, the official said.
Kobane, a Kurdish town on the Syrian-Turkish border, now is witnessing a fierce battle between Kurdish fighters and the IS.
According to US military, IS has shelled the city at least 16 times.
If the IS were to capture Kobane, that would mean it would control land between the north Syrian city of Raqqa and Turkey, an area of about 100 km.
US warplanes had struck the city Friday and Saturday.