Turkish President Recep Tayyip Erdogan has told his American counterpart that Turkey is ready to eject "Islamic State" from Raqqa, its de facto capital in Syria.

But in a phone call with US President Barack Obama on Wednesday evening, he urged the United States not to let Syrian Kurdish forces known as the People Protection Unit (YPG) get involved in any attack to reclaim Raqqa.

"Last night we had a long conversation with Obama and shared our plans with him. We said, 'Come let's kick Daesh out of Raqqa together,' " Erdogan said, referring to the Arabic acronym for "IS."

Complex negotiations

Kurdish fighters have been a key part of the battle against the Islamist militants in Iraq and Syria. But Turkey regards the YPG as a terror organization and claims it has links to the outlawed Kurdistan Workers' Party (PKK).

Erdogan told Obama his troops first planned to take al-Bab, a city east of Aleppo, before moving to Minbij, which is controlled by Syrian Kurds, and then finally move on to Raqqa.

But Gen. Stephen Townsend, the US commander of the anti-"IS" coalition, insisted on Thursday that the Syrian Democratic Forces, which are dominated by the YPG, were "the only force" capable of defeating the militants in the short-term.

Erdogan's new push comes after Turkish jets and forces hit Kurdish fighters in recent days as they compete to capture land from "IS," further complicating the multi-fronted conflict in Syria, which has pitted President Bashar al-Assad's regime against Syrian rebels, independent of the fight against the jihadi group.

Washington has said operations to isolate Raqqa could begin within weeks, possibly before the conclusion of a similar campaign to retake the Iraqi city of Mosul. Turkey has been excluded from the operation in Mosul, in preference of Kurdish Peshmerga fighters.

The need to capture Raqqa is becoming more urgent as "IS" forces retreat from Mosul and other areas of Iraq to its unofficial capital.

On Thursday, Turkish Defense Minister Fikri Isik was insistent that the Ankara government could present an "alternative" fighting force to strike Raqqa.

"Turkey has the capacity to form an alternative ... a sufficient force will be formed with the people of the region" especially the Turkish-backed Syrian opposition, he was cited by the state-run Anadolu Agency as saying.

mm/sms (AFP, AP, dpa, Reuters)