ANKARA, Turkey—The imprisoned leader of Kurdish rebels has outlined a peace plan in which his fighters would declare a cease-fire by March and lay down arms and begin retreating from Turkey in the summer, officials said Wednesday.

Turkey's government said in December that it is engaged in talks with Abdullah Ocalan, who has been held in a prison island off Istanbul since 1999, with the aim of convincing his autonomy-seeking rebel group to disarm and end the 28-year-old conflict that has killed tens of thousands of people since 1984.

Deputy Prime Minister Bulent Arinc told private NTV television in an interview that Ocalan had sent letters to a Kurdish political party and rebel commanders calling on the fighters to halt attacks as of the March 21 spring festival of Nowruz, which is celebrated by Kurds and is usually the scene of violent clashes between Kurds and Turkish security forces. Ocalan also wants his Kurdistan Workers' Party, or PKK, to lay down arms around July and August and start withdrawing from Turkey, Arinc said.

Kurdish legislator Nazmi Gur confirmed to The Associated Press that the Kurdish party had received a 20-page letter from Ocalan outlining his proposals for peace, but did not disclose any of the details.

"It's his draft peace proposal," Gur said. "The ultimate version will take shape after input and proposals from the (Kurdish) party and others involved."

Turkish officials have not revealed details of their talks with Ocalan, but said they were aiming for a deal that would include the declaration of a cease-fire and thousands of rebels' withdrawal from Turkish territory to bases they hold in northern Iraq. Prime Minister Recep Tayyip Erdogan has said the rebels would not be attacked while retreating from Turkey.

Sabah newspaper and other media said Ocalan's proposal foresees the PKK fighters' withdrawal from Turkey by Aug. 15, when the group marks the anniversary of the start of its armed struggle in 1984.

In return, Ocalan "expects" Turkey to release hundreds of Kurdish activists from prisons, ensure that Kurdish rights are safeguarded in a new constitution and grant more powers to local administrations, the newspaper said. The plan does not envision autonomy or a federation for Kurds, it said.

Sabah also said Ocalan had asked Turkey's legal Kurdish party, the Peace and Democracy Party, and the PKK to respond to his letter within two weeks.

"This is a historic process," Gur, the Kurdish legislator said, adding that there was widespread support by Kurds for peace.

He said however, that Kurds, who make up around 20 percent of Turkey's population of about 75 million, would be watching closely to see if Turkey carries out reforms.

Turkey is expected to amend its legislation in a way that would no longer make it a crime to publicly praise Kurdish rebels, which could lead to Kurdish activists' release from prison. Political parties are also working to draft a new constitution, which Kurds hope will improve minority rights.

"We are still at the start of a very difficult process," Arinc said. "We must not be dreamers, but we must remain hopeful."

Erdogan said late Tuesday his government was determined to end the conflict with the PKK, saying he "would drink poison" if needed to achieve peace.

But officials have also said Turkey has no intention of halting its military drive until the rebels lay down arms and Firat news, a website close to the rebels, said Turkish jets had pounded some suspected Kurdish rebel targets in a cross-border raid in northern Iraq late Tuesday. There was no official confirmation of the raid.

The PKK is designated a terrorist organization by the U.S. and the European Union.

In November, hundreds of Kurdish prisoners linked to the PKK heeded a call from Ocalan and abandoned a hunger strike pressing for greater Kurdish rights and improved prison conditions for the rebel leader. The incident demonstrated Ocalan still holds sway over the rebels even after 13 years of being in prison.

In a brief message conveyed by a group of Kurdish legislators who were allowed to visit Ocalan last week, Ocalan suggested that the PKK could release some government officials and soldiers it has captured.

But rebel leader Duran Kalkan was quoted by Firat news as saying that such a step would only be possible if "the democratic process advances" and there is a "softening of the atmosphere."

Arinc said: "I believe the (captive soldiers and officials) could be returned to their families, but this is not a matter that can be used for bargaining."