Kurdish forces remain in control of most of the Syrian border town of Kobane and Islamic State militants have been unable to advance in the past several days.
The situation was still "tenuous" but for the moment, Kurdish forces were holding their ground and US air strikes had slowed the momentum of the IS group, Rear Admiral John Kirby said.
"The situation in Kobane still remains tenuous. We do assess that Kurdish forces in the city are in control of the majority of the city," Kirby said.
"That said, ISIL (Islamic State group) forces continue to threaten it" and still had fighters in "some strength" in parts of the town, he said.
"We've been watching this now for weeks. Certainly in the last several days at least, we know ISIL hasn't made any progress inside Kobane," he said. "But it can change."
US aircraft kept up raids overnight in support of the Kurds, after American C-130 cargo planes dropped ammunition and medical supplies to the Kurdish forces early on Monday.
The small arms and ammunition were provided by Kurdish authorities in Iraq.
Kobane, located near the Turkish border, has become the focus of world attention and turned into a high-stakes symbol in the war against the IS group.
The Sunni extremists are fighting to expand areas under their control in Iraq and Syria while a US-led coalition is carrying out air raids in a bid to halt their advance.
US arms airdrop 'falls into IS hands in Syria'
A US military airdrop of weapons meant for Kurdish fighters fell into the hands of the Islamic State group near the Syrian battleground town of Kobane.
The US Air Force parachuted crates of weapons, ammunition and medical supplies on Sunday night to resupply Kurds defending the Syrian town of Kobane from IS militants.
"One load was taken by IS and there are contradictory reports about a second" which was also reported to have gone astray, said the Syrian Observatory for Human Rights.
Some sources said two consignments had landed in the hands of IS, but others said that warplanes from a US-led coalition destroyed one of them once the error was detected.
But US Central Command, which oversees US forces in the Middle East, said yesterday that only one of 27 bundles had gone astray and that US warplanes bombed it to prevent it being snatched by IS.
In a video posted on the internet, titled "Arms and ammunition dropped by US planes in an IS-held area of Kobane", a masked gunman shows off what appears to be one such bundle attached to a parachute.
"This is the American aid thrown to the infidels," he said, opening wooden boxes filled with rockets and grenades, as aircraft could be heard circling overhead.
"Praise be to God, this is booty for the mujahedeen (Islamic warriors)."
