A California man who is fighting alongside a Kurdish militia against the Islamic State (IS) group in northern Syria has said that intense clashes with militants are continuning in the town of Tel Tamer, close to the border with Turkey and 40 kilometers north of Hasakah city.

The American fighter, who goes by the Kurdish nickname "Sores," (pronounced "Shoresh") is one of a number of Westerners fighting alongside the Kurdish People's Protection Units (YPG) militia in Syria.

"It's an extremely intense fight," Sores told a Kurdish news channel on March 15.

Sores said that for six days, the YPG militiamen had been "going back and forth, battling within grenade range" of the militants.

"We're holding strong though, and we're killing them every chance we get," the American militiaman added.

Sores praised the YPG fighters alongside whom he is fighting in Tel Tamer, saying they are "incredibly fierce warriors."

"We are doing everything we can to free the people from ISIS, Daesh, the fascists that they are. God willing, we will kill every last one of them to help protect these innocent people," he said, using alternative names for the IS group.

Backed by coalition air strikes, the YPG has made significant gains in northeastern Syria in recent weeks, cutting off a strategic supply route from Iraq.

According to the Lions of Rojava Facebook page, which is run by Western veterans who have joined the ranks of the YPG to fight IS, the militants are pushing to retake territory in the northeast that was recaptured by Kurdish militias.

Kurdish forces have recaptured the towns of Tel Hamis and Tel Brak, the Lions of Rojava wrote on March 15.

The IS pushback has been fierce, however, with militants using tanks and other heavy weapons. Among the YPG casualties in the heavy clashes was the first female Western foreign fighter to have joined the Kurdish militia, a German woman named as 19-year-old Ivana Hoffmann. Hoffmann died in Tel Tamer on March 7.

Kurdish officials said on March 14 that U.S.-led war planes had struck IS positions close to Tel Tamer overnight on March 13 and 14.

YPG spokesman Redur Xelil told Reuters on March 14 that fighting "continues around Tel Tamer but the coalition war place have targeted the area, the last strikes were a short while ago."

Pan-Arabic news outlet Asharq Alawsat reported on March 15 that the coalition air strikes around Tel Tamer came after the YPG had appealed for support. YPG spokesman Xelil said that the Tel Tamer area had been the only region where Kurdish forces had been fighting IS militants without coalition air support.

Xelil made his appeal on March 13, calling on the U.S.-led coalition to "take part in the battle of Tel Tamir, as it did in Tal Hamis and Tal Brarak, till [sic] now the International Coalition Forces did not provide help and assistance in the battle of Tel Tamir and Seri Kaniye, and they are urged to do their duty."

The YPG and the Kurdish Women's Protection Units (YPJ) are not the only forces fighting IS militants in Hasakah. The Kurdish militia is backed by fighters from Jaysh al-Sanadid (Army of the Valiant), a tribal militia formed by Sunni Arabs from the Shammar tribe. The Syriac Military Council, an Assyrian Christian militia, is also participating in the fight.

-- Joanna Paraszczuk