ISTANBUL, May 10, (Agencies): Turkey on Wednesday slammed as unacceptable a US plan to arm Syrian Kurdish fighters whom Ankara considers terrorists, but the militia applauded a “historic” move that would speed up the defeat of Islamic State (IS) extremists. The issue risks further stoking tensions between Ankara and Washington less than a week before President Recep Tayyip Erdogan heads to Washington to meet his US counterpart Donald Trump, in their first face-to-face encounter as heads of state.The Kurdish Peoples’ Protection Units (YPG) is seen by Washington as the best ally against Islamic State group jihadists in Syria and the prime attacking force in any upcoming assault on their stronghold of Raqqa. But Ankara regards the YPG as a terror group and the Syrian branch of the Kurdistan Workers’ Party (PKK), which since 1984 has waged an insurgency inside Turkey leaving tens of thousands dead. The dispute poisoned ties between the two NATO allies under the administration of former president Barack Obama but Ankara had hoped for smoother ties under Trump. Prime Minister Binali Yildirim said it was “out of the question” for Turkey to accept any direct or indirect help for the PKK.“The United States and Turkey are two major partners in NATO. We don’t believe America would choose a terror group over our strategic relations,” he told reporters. Speaking to A Haber television, Deputy Prime Minister Nurettin Canikli slammed any supply of arms to the YPG “unacceptable”. “We expect that this mistake is to be rectified,” he said. Turkish Foreign Minister Mevlut Cavusoglu added that “every weapon that turns up in their hands is a threat directed toward Turkey”. Pentagon chief Jim Mattis sought to allay Turkish concerns, saying at a news conference in Lithuania the US would work very closely with Turkey over security on its border with Syria. “We have very open discussions about options and we will work together, we will work out any of the concerns,” he said.