Abdullah Ocalan, the jailed leader of Kurdistan Workers' Party (PKK), has called on his followers to lay down their arms, as part of a peace process to end a 30-year insurgency, according to Turkey's main Kurdish party.
Ocalan's message was shared with the public by Yalcin Akdogan, the Turkish deputy prime minister, on Saturday.
"I invite the PKK to attend an extraordinary congress in the spring months in order to make the strategic and historic decision to abandon the armed struggle," Sirri Sureyya Onder, a politician from pro-Kurdish Peoples' Democratic Party (HDP), said quoting Ocalan.
Onder spoke live on television alongside Akdogan, who said the move towards disarmament showed "an important phase in the resolution process has been reached", after the two sides met briefly in Istanbul.
There was no immediate response from PKK commanders who are based in northern Iraq, but the group generally heeds Ocalan's calls.
Ocalan has been serving a life term on the prison island of Imrali in the Marmara Sea since 1999 but retains influence over his fighters.
Al Jazeera's Bernard Smith, reporting from Istanbul, said: "Since Ocalan declared a ceasefire in 2013, this may be one of his most significant statements.
"That ceasefire essentially brought an end to an armed struggle between the Turkish state and Kurdish separatists that has seen more than 40,000 people killed since 1984."
He said the peace process that started has been stalled, and the Kurds say it is because the Turkish government did not introduce the promised reforms.
"The PKK are saying before this extraordinary congress goes ahead it wants to see the government reforms and security bills pushing through the parliament," our correspondent said.
"There is a lot happening in the background before you might ultimately see an announcement that the Kurdish separatists have laid down their arms."
Turkey began talking to Ocalan in 2012 with the aim of ending the conflict that has killed tens of thousands of people since 1984.
President Recep Tayyip Erdogan welcomed the call as "very, very important" but cautioned that earlier calls made by the Kurdish fighters had failed.
The pro-Erdogan ruling Justice and Development Party (AKP) is seeking support from Turkey's estimated 15 million Kurds in parliamentary elections in June in order to change the constitution and imbue Erdogan's office with more executive powers.
The government has repeatedly said it expects Ocalan to declare an end to the PKK's armed struggle for greater autonomy and cultural rights for the Kurds.
Ahmet Davutoglu, Turkish prime minister, also praised the statement as the start of a new phase, saying the language of violence would now "cease to exist".
A spokesperson for Federica Mogherini, EU foreign policy chief, welcomed Ocalan's comments as "a positive step forward in the peace process", urging all parties to "seize the opportunity" and promising political and practical support.
Ocalan's statement came after an HDP delegation met PKK fighters for talks at their base in the Kandil Mountains in Iraq on February 23 and met Ocalan himself on Friday.
Source: Al Jazeera and agencies