Transport Minister Binali Yildirim will be the sole candidate for the AK Party leadership at a special party congress on Sunday.
With the departure of Prime Minister Ahmet Davutoglu, Turkish President Recep Tayyip Erdogan is one step closer to ultimate power.
The two leaders had been locked in a bitter feud.
Ankara has agreed to take back all undocumented migrants who crossed to Greece, including Syrian refugees.
Ahmet Davutoglu told reporters Monday that "no Turkish prime minister or president will apologize ... because of doing our duty."
Moscow denies the claim.
Syrian troops and militia backed by Russian warplanes mounted what appeared to be their first major coordinated assault on Syrian insurgents.
The new cabinet includes pro-Kurdish and nationalist legislators.
The NATO member is undergoing the worst political uncertainty in decades.
"The outcome is negative," a senior CHP official said.