A weapons-free withdrawal by Ocalan's Kurdistan Workers Party would have been seen as a significant step towards ending the conflict.
Ocalan's supporters have gathered to celebrate his April 4 birthday in southeast Sanliurfa province, where he was born. In a message read out there on Wednesday evening, he appealed for their support for the process, saying he had fulfilled his role.
"I am calling on everyone who says 'I am honourable', whether rich, poor, male, female, young or old, to conform with and develop this (peace) process," he said in a message read out to the crowd in the district of Halfeti.
His supporters set off fireworks and chanted "Long live the leader Apo (Ocalan)" as the message was read out, the Kurdish Firat news agency reported.
"I hope that not a drop of blood will be shed as this process develops. Nobody should harm another. Everyone should participate in this process with love," he said.
Later on Thursday, Erdogan will meet the members of a new 63-strong "wise people commission", made up of academics, journalists and performing artists, established by the government to promote the process nationwide.
A deputy from Erdogan's ruling AK Party presented on Wednesday a proposal to form a parliamentary commission to assess the peace process. The withdrawal will be monitored by Turkish intelligence and the Kurdistan regional government.
The PKK, designated a terrorist group by Turkey, the United States and European Union, launched its insurgency with the aim of carving out an independent state in mainly Kurdish southeast Turkey, but later moderated its goal to autonomy.
Pro-Kurdish politicians are focused on expanding minority rights and stronger local government for the Kurds, who make up about 20 percent of Turkey's population of 75 million people. (Additional reporting by Gulsen Solaker and Jonathon Burch in Ankara; Editing by Nick Tattersall and Alistair Lyon)