Under a roadmap to end the three-decade-old insurgency, the Kurdistan Workers Party (PKK) began in May withdrawing its estimated 2,500 fighters from Turkey to safe havens in Iraq's autonomous Kurdistan region.
No deadline was set for the withdrawal, but a ceasefire agreement reached in March said the peace process could not proceed further until it is completed.
In a statement cited by Firat News, the PKK armed movement said "the Turkish government's attitude of not progressing on the Kurdish question was behind this situation", but it vowed to respect the ceasefire with Turkish forces.
"The truce will be maintained... To allow the Justice and Development Party (AKP) government to begin initiatives supporting the (peace) plan" of Abdullah Ocalan, the imprisoned PKK leader, it said.
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In the statement, the PKK accused the government of failing to pass a package of democratic reforms designed to reinforce the rights of Turkey's Kurdish minority, believed to number up to 15 million.
In return for withdrawing its fighters in Turkey, the PKK is demanding amendments to the penal code and electoral laws as well as the right to education in the Kurdish language and a degree of regional autonomy.
Erdogan also questioned the extent of the PKK pullout, estimating that barely 20 percent had left Turkey for bases in Iraqi Kurdistan and that most were children or elderly.
Ocalan has been in negotiations since late 2012 with Turkish authorities for an end to the Kurdish conflict, which has cost more than 40,000 lives since 1984.
Ocalan, serving a life sentence for treason and separatism since 1999 in a jail on Imrali island, off Istanbul in the Sea of Marmara, announced a historic ceasefire with the government in March.