Now in his 60s, Hekmatyar has been exiled since the Taliban came to power in 1996 and drove him out of the country. Hezb-i-Islami is often described as the second-largest insurgent group in Afghanistan, but his fighters have little presence on the battlefield and many of Hekmatyar’s former loyalists have defected to the much larger Taliban.

Still, a deal would be a slight boost for Afghan President Ashraf Ghani, whose effort to make peace with Afghanistan’s insurgent groups has been flagging as the Taliban continues to battle government forces.

The outlines of an agreement, which were reported by multiple sources Saturday, would require Hezb-i-Islami’s military wing to lay down its arms, respect the Afghan Constitution and cut off ties with any other armed opposition groups.

In return, Hezb-i-Islami fighters in government custody would be released and given the same amnesty granted to other militant groups that were formed to fight the Soviet occupation of Afghanistan during the Cold War and are accused of killing civilians.

Mohammad Umer Daudzai, a former interior minister, praised Hekmatyar’s support for peace but said he doubted it would affect the course of the fighting.

“Hekmatyar has not been a major force in the war in quite a while,” Daudzai said.

Once one of the favourite clients in Afghanistan for US and Pakistani intelligence, Hekmatyar gained a reputation as a power-hungry extremist who came to denounce his US patrons. After taking CIA support to fight the Soviet occupation of Afghanistan, he battled his fellow mujahedeen commanders during a civil war in the 1990s.

His forces and other factions shelled Kabul indiscriminately in those years and are accused of causing thousands of civilian deaths. He negotiated his way to the prime ministership before the Taliban pushed him out when it came to power.

Now believed to be living in Pakistan, Hekmatyar was designated a “global terrorist” by the U.S. government and had close ties with bin Laden when the al-Qaida leader was based in Afghanistan. Even as Hekmatyar’s support has waned — Hezb-i-Islami’s political wing has a presence in parliament and the Cabinet but does not have ties to him – he retained a measure of influence with writings and recorded speeches in which he often rails against the United States.

The talks between Hekmatyar’s group and the government’s High Peace Council were reportedly held in Kabul over the past two months. In an interview with the Pajhwok news agency, Mohammad Amin Karim, the group’s lead negotiator, said Hekmatyar’s return to Afghanistan was up in the air but the group asked Kabul to seek the removal of his name from the U.S. blacklist.

Like other former militia commanders blamed for war crimes — including Abdul Rashid Dostum and Mohammad Mohaqiq, both senior figures in the government — Hekmatyar would be shielded from prosecution under a 2007 amnesty law passed under President Hamid Karzai.

Pajhwok reported Sunday that Ghani was due to discuss the talks with members of parliament. In a sign of how he might try to sell the agreement, his wife, Rula Ghani, said Hekmatyar and other former mujahideen leaders were “old people” who should be allowed back home.

“They are ending their lives,” Rula Ghani told an audience at the United States Institute of Peace in Washington over the weekend. “If they want to come to Afghanistan and finish their lives where they were born, I think it is only the human way to say, ‘OK, you come, but we put some conditions.’”

The news of the deal comes just weeks after Ghani declared that he would suspend efforts to begin direct talks with the Taliban, a centerpiece of his foreign policy since taking office in August 2014.

Months of meetings among diplomats from Afghanistan, Pakistan, the U.S. and China had failed to bring Taliban leaders to the negotiating table. Meanwhile, Taliban fighters continued to battle government forces.