Ankara: Turkey's military said it killed 14 members of the group Kurdistan Workers Party (PKK) in air strikes in northern Iraq on Saturday, as Ankara steps up a push against the group and their affiliates in Iraq and Syria. Turkey has intensified attacks on the PKK in northern Iraq and its Syrian-Kurdish affiliate, the YPG, in northern Syria. President Tayyip Erdogan said on Saturday that as many as 220 militants had been killed in recent strikes elsewhere in northern Iraq. Six militants were killed around the area of Sinat-Haftan and eight in the countryside around Adiyaman in two separate air strikes in northern Iraq on Saturday morning, the military said in a statement. The PKK, which has carried out a three-decade insurgency against the Turkish state, has camps in the mountains of northern Iraq. Both the United States and Turkey consider it a terrorist organisation. However, the NATO allies disagree on the Syrian-Kurdish YPG, which the United States sees as a useful partner in the fight against IS in Syria. Erdogan considers the Syrian-Kurdish fighters to be a terrorist group and is concerned their advances in northern Syria could fuel the Kurdish insurgency at home. He is expected to raise the issue when he meets with U.S. President Donald Trump next month. "We tell our American friends not to take terrorists with them," Erdogan said in comments broadcast live on network NTV. He reiterated his position that he does not want the United States to use the YPG in the fight to take Raqqa, IS's de facto capital in Syria. "America, coalition forces and Turkey can join hands and Raqqa will turn into a graveyard for Daesh," he said, using an Arabic name for IS. He said some 210-220 militants had been killed in recent air strikes elsewhere in northern Iraq. Meanwhile, a commander of the Syrian Kurdish YPG militia said on Friday U.S. forces would begin monitoring the situation along the Syria-Turkey frontier after cross-border fire between the Turkish military and YPG this week. The monitoring had not yet begun, but the forces would report to senior U.S. commanders, Sharvan Kobani told Reuters after meeting U.S. military officials in the town of Darbasiya next to the Turkish border. The officials had toured Darbasiya which was hit by Turkish artillery fire earlier in the week. Turkish warplanes carried out air strikes against Kurdish militants in northeastern Syria and Iraq's Sinjar region on Tuesday in an unprecedented bombardment of groups linked to the PKK, which is fighting an insurgency against Ankara in Turkey's southeast. Those attacks killed nearly 30 YPG fighters and officials, a monitoring group reported. Since Tuesday the YPG and Turkish forces have traded artillery fire along the Syria-Turkey border. Turkey's bombardment of YPG positions complicates the U.S.-backed fight against IS in Syria, where the YPG has been a crucial partner on the ground for Washington. The YPG is a key component of the Syria Democratic Forces (SDF), a U.S.-backed alliance of Arab and Kurdish fighting groups involved in a campaign to drive IS out of its Syria stronghold, Raqqa. U.S. NATO ally Turkey views the YPG and other PKK-affiliated groups as terrorists. Pentagon spokesman Captain Jeff Davis said on Friday U.S. troops were deployed along the border. "We continue to urge all the parties involved to focus on the common enemy which is IS," he told reporters. Hundreds of U.S. troops are deployed on the ground in Syria to support the Raqqa offensive.