Taliban co-founder Mullah Abdul Ghani Baradar arrived in Kabul on Saturday for talks on establishing a new "inclusive" government in Afghanistan, a senior official said.

It comes after other senior Taliban leaders were seen in the capital in recent days, including Khalil Haqqani -- one of America's most wanted terrorists with a $5 million bounty on his head.

A senior Taliban official told AFP that Baradar would meet "jihadi leaders and politicians for an inclusive government set-up".

Hours later, pro-Taliban social media accounts showed Haqqani announcing that Ahmad Massoud -- the son of Afghanistan's most famed anti-Taliban fighter Ahmad Shah Massoud -- had "declared allegiance" to the movement.

Massoud had earlier this week appealed to the United States to supply arms to his resistance movement in the Panjshir Valley, northeast of Kabul, saying he wanted to follow in his father Ahmad Shah Massoud's footsteps.

Massoud has not issued a statement.

Haqqani has also met with Gulbuddin Hekmatyar -- a former bitter rival during the brutal civil war of the early 1990s, but still influential in Afghan politics.

Taliban co-founder Mullah Abdul Ghani Baradar has arrived in Kabul for talks on establishing a new government in Afghanistan
Taliban co-founder Mullah Abdul Ghani Baradar AFP / KARIM JAAFAR

Baradar arrived in Afghanistan last Tuesday from Qatar, choosing to touch down in the country's second-biggest city Kandahar -- the Taliban's spiritual birthplace.

Within hours of his return, the group announced its rule would be "different" this time.

But they have given few details about who would form their government.

Arrested in Pakistan in 2010, Baradar was in custody until pressure from the United States saw him freed in 2018 and relocated to Qatar.

He was appointed head of the Taliban's political office in Doha, where he oversaw the signing of the agreement last year that led to the withdrawal of US forces and an end to their 20-year campaign.

The Taliban scotched any hopes of a negotiated peace deal with the Afghan government by overrunning the country in under two weeks -- a lightning offensive that ended with them taking Kabul unopposed last Sunday.

On Friday, Haqqani -- the uncle of Taliban deputy leader Sirajuddin Haqqani -- was seen leading prayers at a mosque in Kabul.

Another key leader of the feared network -- Anas Haqqani -- was also in the capital and had met former president Hamid Karzai and Abdullah Abdullah, who led the overall peace process for the previous administration.