YPG convoy
© ReutersKurdish fighters from the People's Protection Units (YPG) head a convoy of U.S military vehicles in the town of Darbasiya next to the Turkish border, Syria.
The Department of Defense has confirmed delivery of heavier weapons to US-allied Kurdish fighters, for the upcoming 'long and difficult' battle to retake the Syrian city of Raqqa from ISIS. The Pentagon has also offered protection to its NATO ally, Turkey.

"That's not to say we all walk into the room with exactly the same appreciation of the problem or the path forward," Mattis told reporters in Denmark after meeting with officials from more than a dozen nations also fighting IS. "We're going to sort it out," Mattis said. "We'll figure out how we're going to do it."

US Secretary of Defense James Mattis is meeting with Turkish officials in Copenhagen, Denmark, on Tuesday to work out differences over the US's continued support for Syrian Kurds against Islamic State (IS, formerly ISIS/ISIL) fighters and efforts to retake Raqqa. Turkey considers them an extension of a banned terrorist group on its territory.

Back in February, General Joseph Votel, commander of the US forces in the Middle East, after visiting the Raqqa frontline told reporters Kurdish-led Syrian Democratic Forces need more than AK-47s weapons in the fight against Islamic State (IS, formerly ISIS/ISIL). "Anti-tank weapons systems to address the vehicle-born IEDS. Certainly mortars would be something of help," Votel said, according to CBS News. "Things that they would need of a force that's going to conduct an assault."

Syrian Kurds have complained that while asking for heavier weapons all the US has supplied are small arms and ammunition.