Senior members of the Afghan Taliban said on Thursday that a prominent figure within the militant group who had opposed its new leadership has now pledged his allegiance, helping to close divisions within the Taliban ahead of possible peace talks with the government.

Abdul Qayum Zakir had disagreed with the appointment of Mullah Akhtar Mansoor as leader of the Taliban following the death of the movement’s one-eyed founder, Mullah Mohammad Omar.

Two Taliban members — Mohammad Ghaus, a foreign minister in the Taliban’s 1996-2001 regime, and ruling council member Mullah Gul Rahman Saleem — told The Associated Press that Zakir had recently pledged allegiance to Mansoor.

His loyalty pledge helps close one of several rifts that emerged after Mullah Omar’s death was announced by the Afghan government last summer.

Mansoor had led the movement in Omar’s name for more than two years after he died. Kabul’s announcement of Omar’s death elevated Mansoor to the leadership, but led to deep mistrust among some at the top of the insurgent movement who felt betrayed.

The announcement of Omar’s death also derailed a peace process that has yet to be revived. The Taliban recently announced they would not attend direct talks with Afghan government representatives, which Kabul officials had said would take place in early March.

Zakir’s return to the fold follows a rallying call issued by Mansoor earlier this month, in which he called on disaffected Taliban to reunite under his leadership. This appears to be an attempt to strengthen his position ahead of any peace dialogue, consolidating battlefield gains made after the international combat mission ended in 2014 and left Afghan forces to fight largely alone for the first time in the war’s 15 years.

Zakir, a former Taliban military commission leader who spent time in Guantanamo Bay prison after the 2001 U.S. invasion toppled the Taliban regime, held a number of senior roles within the group, both during its rule of Afghanistan and after it went into exile in neighboring Pakistan. He had initially opposed Mansoor’s elevation to leader, but chose to keep a low profile.

His power base is in southern Helmand province, where most of the world’s opium is produced, and where Mansoor is believed to control the bulk of the smuggling routes.

Another dissident, Mullah Mohammad Rasool — known to be close to Zakir — established his own militia in western Afghanistan, where he fought Mansoor’s men. Reports circulated in the Pakistani media early this month that he had been lured back to Pakistan and arrested by authorities there. Islamabad has not confirmed the reports.