The U.S. faces a hard balancing act in trying to assuage Turkish concerns about Kurdish YPG forces while still achieving its goal of booting ISIS from the territory it seized in the early years of the Syrian civil war.
The UN special envoy on Syria, Staffan de Mistura, says he has also asked the warring parties to return to Geneva later in March as efforts intensify to end Syria's six-year conflict, which has killed an estimated 300,000 people and displaced millions more.
Turkish President Recep Tayyip Erdogan considers the Syrian Kurdish YPG, or People's Protection Units, to be a terrorist group linked to separatists in southeastern Turkey.
US General Stephen Townsend, commander of the Combined Joint Task Force-Operation Inherent Resolve told reporters that he was concerned about the convergence of Turkish, Russian, Syrian regime and ISIS forces on areas near Manbij.
Though after the August invasion Turkey initially focused on ISIS targets, they have always said their intention was to exterminate both ISIS and the YPG, and recently, indications are they are keen to move more against the Kurds than against ISIS.
In the case of Raqqa, the idea is that Syrian forces will do the bulk of the fighting on the ground but Americans will assist them by providing advisers as well as firepower.
Though the USA has been hoping to include both Turkey and the battle-hardened Kurdish forces, Yildirim insisted Turkey wouldn't be part of any operation including the Syrian Kurdish force known as the YPG, considered by Ankara to be terrorists who threaten Turkey's security. Turkey says no decision had been made yet on who would carry out the final assault while the US-led coalition said a possible Turkish role remained up for discussion.
Also Friday, Turkey's military said Turkish troops and Turkey-backed Syrian opposition forces have killed - or "neutralized" - 71 Syrian Kurdish fighters in northern Syria this week.
US spokesman Col. John Dorrian insisted the USA military has seen no evidence Kurdish forces are "doing anything to threaten Turkey", and that the United States remains open to a "Turkish role in liberating the city".
Syrian Democratic Forces said they have enough manpower to take Raqqa without the Turkish-backed rebel force, drawing support from locals in villages and towns they have captured from Daesh.
When did Scotland last beat England at Twickenham in the Six Nations?
Eddie Jones has a name for his bench - he calls them the finishers and they certainly have plenty of firepower to call upon. "I like having that pressure and we have had a couple of wins and let's make it a third".
The report comes as the militants come under mounting pressure by rival us -backed and Russian-backed forces working to seize the capital, Raqqa.
To put things into context, the U. has imposed genocidal sanctions on Syria which deprives ordinary Syrians of the basic necessities of life, while spending billions of dollars every year to train and arm so called rebel forces, and has used depleted uranium which is a war crime and act of genocide.
The US has clarified that it is taking measures to avoid clashes between the YPG and Turkish forces.
Retaking Raqqa would push the Islamic State out of its greatest stronghold in Syria and back into a relatively small patch of territory in eastern Syria, but it would not be a death blow to the group.
U.S. Lt. Gen. Stephen Townsend, of the anti-IS coalition, said all the forces acting in Syria have converged "within hand-grenade range of one another".
Votel went on to explain that the local forces the U.S.is supporting in Syria, "don't have as good mobility, they don't have as much firepower, so we have to be prepared to fill in some of those gaps for them and that may involve additional fire support capability, a variety of other things that we bring in to help offset some of the gaps that they have and we take the burden on ourselves for that aspect of the fight".
The Pentagon has maintained that the fight against ISIS is authorized by a 2001 Congressional resolution, which authorizes the President to use "necessary and appropriate force" against the "nations, organizations, or persons" involved in the 9/11 attacks.
Turkey ultimate intention in pressuring Manbij may be to keep the SDF out of the Raqqa offensive.
Ahmed said if the US wants the Raqqa campaign to move ahead, "they must protect Manbij".