ISTANBUL — Abdullah Ocalan, the imprisoned leader of a Kurdish militant group that has fought a decades-long insurgency against Turkey, issued a call from prison on Thursday asking the movement he founded to lay down its arms and dissolve itself.

The comments by Ocalan, who heads the Kurdistan Workers’ Party, or PKK, were read at a news conference in Istanbul by Kurdish lawmakers and leaders who met with Ocalan on Thursday. His appeal, under the heading “Call for Peace and Democratic Society,” came a decade after the last negotiations between Turkey and the PKK broke down, and raised the prospect of an end to a conflict that since the 1980s has killed an estimated 40,000 people.

“The outright denial of Kurdish reality, restrictions on basic rights and freedoms — especially freedom of expression — played a significant role” in the PKK’s “emergence and development,” his statement said, in an appeal to Kurds, who make up roughly one-fifth of Turkey’s population.

The statement called on the PKK, which is designated as a terrorist organization by Turkey, the European Union and the United States, to “convene your congress and make a decision; all groups must lay their arms and the PKK must dissolve itself” — a sweeping appeal that went further than calls for ceasefires issued in the past.

Questions remained, including whether Ocalan’s appeal would be heeded by the PKK’s militant cadres based in the mountains of northern Iraq. Turkey is also fighting against PKK-linked militants in Syria, both in direct military engagements and through Syrian proxy forces.

Ocalan founded the PKK in 1978. He was arrested just over two decades later, in Kenya. He was convicted of sedition and treason and sentenced to a life term on Imrali, a prison island near Istanbul.

Turkey and the Kurdish militants have paused fighting in the past, including for a period beginning in 2013, when Ocalan, after negotiations with Erdogan’s government, issued a statement that recognized new political realities in both Turkey and the Middle East, which was then emerging from the Arab Spring uprisings. Ocalan also called for armed PKK elements to withdraw from Turkey, in a truce that only lasted for 2½ years.

Signs of a new opening between Turkey and the PKK began emerging last fall, when Devlet Bahceli, the leader of a Turkish hard-right nationalist party and a political ally of Erdogan, expressed support for the eventual release of Ocalan.

Bahceli suggested Ocalan could be paroled if he renounced violence and disbanded his organization. “Let them show that they are thirsty for brotherhood, not blood,” Bahceli said. At the opening of parliament on Oct. 1, Bahceli, in an uncharacteristic gesture, shook hands with lawmakers from the pro-Kurdish People’s Equality and Democracy Party, or DEM.

Erdogan, backing Bahceli’s call, spoke of a “historical window of opportunity.”

As negotiations continued over the revival of a peace process, DEM party members made three visits to Ocalan in prison, including on Thursday.

For Erdogan, the push to restart the peace process with the PKK may have domestic benefits, analysts said, including by extending his term as president beyond its current limit in 2028. Erdogan’s party and its nationalist coalition ally “may be angling to obtain the backing of the DEM Party in parliament to write up a new constitution that would enable Erdogan to run again,” Alper Coskun and Sinan Ulgen wrote in a commentary for the Carnegie Endowment for International Peace in the fall, after Bahceli’s outreach.

“Or, if that fails,” they wrote, “this new alliance would try to pass a parliamentary decision for early elections before the end of Erdogan’s mandate in 2028.”