The Turkish president, Recep Tayyip Erdoğan, has accused the US of supporting Kurdish militants, after Turkish troops found the bodies of 13 Turkish soldiers, police and civilians abducted by Kurdish insurgents in a cave complex in northern Iraq. Erdoğan also took aim at the state department after its initial hesitance to blame the Kurdistan Workers’ party (PKK). “You are with them and behind them, pure and simple,” Erdoğan said. Both Turkey and the US view the PKK as a terrorist organisation but the US has also backed a Kurdish militia linked to the PKK in neighbouring Syria. “If we are together in Nato, and if we are to continue our [alliance] in Nato, you have to be sincere toward us,” Erdoğan said. The Turkish foreign ministry summoned US ambassador David Satterfield to convey Ankara’s displeasure “in the strongest possible terms”. The foreign minister, Mevlüt Çavuşoğlu, expressed Turkey’s unease over recent US statements during a telephone call with the US secretary of state, Antony Blinken, his ministry said. In their first conversation since President Joe Biden’s administration took office last month, the two also discussed other disagreements between the Nato allies and agreed to “develop an open and sincere dialogue based on mutual respect”, the ministry said. State department spokesman Ned Price said Blinken expressed condolences for the deaths of the hostages and “affirmed our view that PKK terrorists bear responsibility”. Blinken also emphasised their shared interest in countering terrorism. After the phone call, Washington issued a new statement explicitly condemning the PKK for the deaths. “The Secretary expressed condolences for the deaths of Turkish hostages in northern Iraq and affirmed our view that PKK terrorists bear responsibility,” Price said. The victims were discovered in the Gara region, near the Turkish border, during an operation against the PKK that had aimed to free the hostages. Twelve of the victims were shot in the head and one died of a shoulder bullet wound. The 13 were kidnapped inside Turkey in 2015 and 2016. Erdoğan said 51 PKK militants were killed during the latest offensive and vowed to press ahead with cross-border offensives. “We have the power, capability and determination to come down hard on the terrorists everywhere,” Erdoğan said. In a statement carried by the PKK-linked Firat news agency, the PKK said “prisoners of war” consisting of members of the Turkish security forces and intelligence agency were killed as a result of Turkish airstrikes. Three Turkish troops also died during the operation to free the hostages and three others were wounded, the defence ministry has said. Tens of thousands of people have been killed since the PKK, which is designated a terrorist organisation by the US and the EU, began an insurgency in Turkey’s majority Kurdish south-east region in 1984.