The Turkish military said the pre-dawn raids targeted "terrorist hotbeds" and supply routes used by the outlawed Kurdistan Workers' Party, or PKK, to smuggle ammunition, weapons and explosive material into Turkey, where it is waging an insurgency.
On Tuesday, Turkey also struck targets near Mount Sinjar in Iraq for the first time, widening its air campaign there. The US Department of State said it was "deeply concerned" the strike was conducted "without proper coordination" either with the US military or commanders within a broader worldwide coalition, which claims to be fighting Daesh Takfiri terrorists in Iraq and Syria.
"We informed our United States allies that we were going to undertake this operation".
"The operations will continue to be carried out from now with the same determination until the very last terrorist is neutralised", it said.
"Turkey acts transparently on all issues". We don't have a hidden agenda.
"We shared this with the USA and Russian Federation and we are sharing it with Iraq as well".
Iraq's Foreign Ministry denounced the strikes as a "violation" of its sovereignty and called on the worldwide community to put an end to such "interference" by Turkey.
Dorrian said Turkey gave the US less than an hour's notice, and declined to be more specific.
"There are terrorists who enter Turkey via different paths", he said.
"We have expressed those concerns with the government of Turkey directly", State Department spokesman Mark Toner told reporters on a conference call.
The Turkish raids showed the challenges facing US -led attempts to defeat Islamic State in Syria and tension between North Atlantic Treaty Organisation allies Washington and Ankara over Kurdish combatants who have been crucial in driving back the jihadists.Ankara sees the YPG as a hostile force and an extension of the outlawed PKK, which has waged a three-decade insurgency against the Turkish state and is considered a terrorist group by Turkey, the United States and the European Union.
But Washington sees the YPG as essential in the fight against IS in Syria.
It repeatedly stressed that it will not allow the Kurds of having a rule in that area. Abdel Rahman said a female Kurdish fighter was among the dead.
Syrian Kurdish forces said the strikes hit a media centre, a local radio station, a communication headquarters and some military posts, killing an undetermined number of fighters in Hassakeh, but the Britain-based Syrian Observatory for Human Rights, which monitors the Syrian war, said 18 members of the YPG were killed. There were no casualties.
"We recognize the threat the PKK poses to Turkey, but Turkey can not pursue that fight at the expense of our common fight against terrorists that threaten us all", Rankine-Galloway said, using the initials for the Kurdistan Workers' Party.
However, Turkey has accused U.S. Kurdish allies - the People's Protection Units, a Kurdish militia in Syria, and the Syrian Democratic Forces - of supporting the PKK.