US warplanes carried out on Wednesday its first air strikes on targets of the so-called ’Islamic State of Iraq and the Levant’ (ISIL) takfiri group in Syria after taking off from a Turkish base.

US warplanes carried out on Wednesday its first air strikes on targets of the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group in Syria after taking off from a Turkish base, kicking off a key new phase in the campaign against the jihadists.

A US drone had last week executed a single lethal air strike against an ISIL target in Syria but this was the first time manned US fighter jets had carried out raids after taking off from Turkey's strategically-located Incirlik base.

Using the Incirlik base outside the city of Adana in southern Turkey drastically cuts the distance needed for the US jets to fly to northern Syria compared with other launch bases further afield in the Middle East.

"Today, the United States began flying manned counter-ISIL missions from Incirlik Air Base, Turkey. Strikes were conducted," Pentagon spokeswoman Commander Elissa Smith said.

Turkey's Dogan news agency said three US fighter jets were seen taking off from Incirlik in the evening.

Last month, Turkey agreed to open up the base to coalition planes for bombing ISIL targets in Syria following months of tough negotiations.

Brett McGurk, deputy US envoy for the anti-IS coalition, meanwhile wrote on Twitter that he was back in Ankara for talks with Turkish officials "to advance our joint cooperation" against ISIL militants.