​Islamic State has published a new video in which a jihadist shows off brand-new American hardware, which was purportedly intended for the Kurds they are fighting in the Syrian border town of Kobani.

The undated video, posted by the unofficial IS mouthpiece “a3maq news”, sees a jihadist showing several boxes of munitions with English-language markings, with a parachute spread out on the ground beside.

Although it is unclear what was the bundle shown in the video, the militant explains that “this is some of the military equipment that was dropped by American forces.”

“These are the bombs that the American forces dropped for the Kurdish parties,” he says. “They are spoils of war for the Mujahedeen.”

On Sunday the US said that three of its Air Force C-130 planes successfully delivered 27 bundles of military and medical supplies, which it said were not from the US, but from Kurds in Iraq.

On Monday, however, the US Central Command admitted that originally there had been 28 deliveries, and a “stray bundle” had to be destroyed “to prevent these supplies falling into enemy hands.”

The Syrian Observatory for Human Rights meanwhile said that the weapons dropped by the US may have ended up in the hands of the militants, AP reports. No independent verification has yet been made of the video showing munitions, hand grenades, and other weaponry.

Russia's UN envoy, Vitaly Churkin says that he is not surprised that IS fighters may have gotten their hands on a US air-drop.

"This is not surprising. Because it is necessary to coordinate clearer (action) with the Syrian government and generally act on the basis of the decisions of the Security Council," Churkin told TASS.

Meanwhile Bashar Jaafari, Syrian envoy to the UN, told the news agency that while he could not confirm that IS has intercepted US weapons, Syria, he says was not notified of US arms drops.

"No, we were not informed (about air drops). They did it only once, when the American permanent representative (Samantha Power) met with me to inform my government through me about the beginning of the military operation,” Jaafari said.

The video itself caused quite a stir on the social media landscape with users“thanking”Washington for delivering the arms into the wrong hands, something the US has in the past vowed to avoid.

White House Deputy National Security Advisor Ben Rhodes meanwhile insisted US cargo always reaches the correct destination and people.

“We feel very confident that, when we air drop support as we did into Kobani… we’ve been able to hit the target in terms of reaching the people we want to reach,” Rhodes told CNN on Monday.

“What I can assure people is that, when we are delivering aid now, we focus it on the people we want to receive that assistance. Those are civilians in need. Those are forces that we’re aligned with in the fight against ISIL [the government’s preferred acronym for IS], and we take precautions to make sure that it’s not falling into the wrong hands.”

The US-led coalition has conducted over 135 air strikes against IS targets around Kobani, including 4 on Tuesday, this week was the first time Washington had delivered arms to Kurdish fighters via airdrop “intended to enable continued resistance against ISIL's attempts to overtake Kobani,” said US Central Command.

Following the delivery, spokesman for the Syrian Kurdish People's Protection Units (YPG) fighting IS forces, Redur Xelil said that the military assistance dropped by “American planes at dawn on Kobani was good... It will have a positive impact on military operations against Daesh (ISIS) and we hope for more.” Xelil also claimed that the delivery drop was coordinated.

The latest weapons claimed by the Islamic State militants will add to the vast arsenal of US weaponry that IS seized in Iraq in a sudden sweep in June. IS launched its offensive on Kobani on September 16 sparking a massive exodus of some 200,000 refugees into Turkey and worldwide protests of Kurds and their supporters.