US would prevent 'unacceptable' Turkish invasion of Syria: Pentagon chief

"We believe any unilateral action by them [Turkey] would be unacceptable,” US Defense Secretary Mark Esper said on Tuesday.
 
Turkey on Sunday repeated a threat to cross into Syria if conditions for a safe zone in the northern part of the country were not met.
 
The Turkish government has long been infuriated by Washington’s persisting support of the People's Protection Units (YPG), a Kurdish militant group in northern Syria, that the US regards it as the main purported fighting force against terrorists of the Daesh Takfiri terrorist group.
 
The YPG plays as the backbone of the so-called Syrian Democratic Forces (SDF), an anti-Damascus alliance of predominantly Kurdish militants.
 
Ankara has declared the YPG as a terrorist group and views it as the Syrian branch of Turkey’s homegrown Kurdistan Workers’ Party (PKK), a terrorist group that has been fighting for an autonomous region inside the Anatolian country since 1984.
 
Turkey wants such a safe zone in northern Syria to be free of the SDF.
 
“We can only be patient for so long,” Turkish President Recep Tayyip Erdogan warned on Sunday.
 
Esper, however, warned Turkey against losing its patience claiming the US could “prevent unilateral incursions that would upset these mutual interests that . . . the United States, Turkey and the SDF share with regard to Syria.”
 
He added that the United States currently has a Defense Department team in Turkey to negotiate with Turkish officials on establishing the safe zone requested by Turkey for the SDF.
 
“We’ve made progress on some of the key issues,” Esper said, evading any details.
 
Esper noted that the US does negotiation with the Kurds “as much as we do with the Turks”.
 
“We have a lot of mutual interests in northern Syria. We want to sustain the continued defeat - at least of the physical caliphate – of ISIS. That becomes a question if [the Turks] move in and the SDF is impacted,” Esper said.
 
“Again, I’m hopeful we’ll work out something to address their security concerns, we just need to take one day at a time and continue to work through the process.”
 
Relations between the United States and Turkey have soured in the past several years.
 
Most recently, Washington moved to pull Ankara from the F-35 fighter jet program.
 
Turkey planned to buy 100 of the fighters, which would have a total value of about $9 billion.
 
In mid-July, US President Donald Trump announced Washington will not sell Turkey the jets over Ankara’s decision to purchase Russian S-400 missile defense systems.
 
Russia’s S-400 missile defense system were said to be not operable with the advanced fighter jets.