KABUL: The confirmed death of the Taliban's reclusive leader Mullah Mohammad Omar has weakened the movement, giving Kabul an opportunity to step up the battle against the insurgency, an Afghan governor and one of the country's most powerful former warlords said Monday.

"Defeating the Taliban is a very real possibility right now and this is the right moment to fight against the Taliban," Atta Mohammad Noor told The Associated Press.

The crisis in the Taliban leadership emerged when Afghan authorities announced last week that Mullah Omar died in April 2013. The Taliban confirmed his death and said Mullah Akhtar Mohammad Mansoor had been elected to replace him.

The insurgents have tried to keep a unified front, but cracks soon emerged, with Mullah Omar's relatives contesting Mullah Mansoor's appointment and demanding a wider vote that includes battlefield commanders who have intensified the 14-year insurgency in recent months.

Pakistan, which is believed to have strong influence over the Taliban, had been mediating peace talks launched last month, but postponed them indefinitely after the announcement of Mullah Omar's death.

Noor, a Tajik from the northern Balkh province, said Kabul should "take control of the peace process." He urged the government to act quickly and call on neighbouring countries, as well as the United States, Britain and the European Union, to push the process forward.

Though he was not seen in public after fleeing to Pakistan after the US-led 2001 invasion of Afghanistan, Mullah Omar's spiritual influence unified the various Taliban factions, Noor said.

"So, on one hand I see that (his death) will speed up the peace and reconciliation process," Noor said. "However, the Taliban will be divided and not working as one entity, so it will be difficult to bring these divided parties to the table."

Noor fought the Soviet invaders throughout the 1980s, and later the Taliban when they ruled Afghanistan. He has been governor of Balkh since 2004 and expects to be reappointed to the position by President Ashraf Ghani.

Until recently, Balkh and most of northern Afghanistan had been largely peaceful. Now, the Taliban and other insurgent groups ─ including the self-styled Islamic State group - have established a presence there, Noor said.

Pakistan, which hosted the first round of official peace talks in early July, holds the key to the peace process, Noor said.

"They (Pakistani officials) can bring the Taliban to the table," Noor said. "Their influence has been proven beyond doubt."

Read more: Taliban power transition raises hopes for Afghan peace talks

Noor also said that Jalaluddin Haqqani, the leader of the notorious Haqqani Network, a militant group that has carried out several major attacks on US and Nato forces, had died 18 months ago.

Also read: Afghan Taliban issues statement quoting 'dead' Jalaluddin Haqqani

A spokesman for Afghanistan's intelligence agency neither confirmed nor denied the report. Haqqani's son, Sirajuddin, was named Mullah Mansoor's deputy after Mullah Omar's death.

President Ghani said Monday that recent developments appeared to be "the end of a bitter stage". Speaking via a video link from Germany, where he is recovering from foot surgery, Ghani said: "Our main goal is peace."

"Peace between Afghanistan and Pakistan, because our country is in an unannounced 14-year war with Pakistan. This war should end and both governments must cooperate," he said.

The Taliban meanwhile issued a statement Monday saying condolences for Mullah Omar and congratulations for Mullah Mansoor had been flooding in from across Afghanistan. "All these messages and support show the people's unity and love toward their Islamic Emirate," it said.

Mullah Mansoor is widely seen as having pushed the Taliban into the negotiations at Pakistan's bidding. Under his proxy leadership as Mullah Omar's deputy, the Taliban intensified their attacks on local security forces after Nato and US troops ended their combat mission last year, while at the same time starting a dialogue with Kabul.