A senior Taliban commander has released a letter proposing a new strategy for the movement that includes negotiating with the United States and other Western governments.

In a statement to top Taliban members, Mullah Qayyum Zakir said the leadership of the movement must embrace new internal and external policies.

Zakir's 12-point proposal includes negotiating with the Kabul administration and foreign governments on the implementation of Islamic law, and improving military strategy and coordination within the group.

However, Zabihullah Mujahid - the Taliban spokesman and a close aide of its leader Mullah Akhtar Mansoor - said Zakir's proposal had not been received.

Left Behind: US' Afghan translators

"We don't know anything about the new strategy, but I will keep saying that we are not going to negotiate with foreign governments and will only focus on bringing back Sharia [Islamic] law," Mujahid told Al Jazeera.

Al Jazeera's Jennifer Glasse, reporting from Kabul, said if the proposal was accepted it would represent a significant shift for the Taliban, which has long demanded the full withdrawal of all Western forces from Afghanistan before any negotiations with the government take place.

Mullah Zakir was long seen as a rival to the new Taliban leader Mansoor. After his appointment Zakir refused to pledge allegiance to him.

However, last month Zakir was reported to have finally pledged fealty.

Rifts within the Taliban

Mullah Mansoor's appointment was disputed amid reports of rifts within the leadership emerging. Violent clashes were reported between two rival Taliban groups in southern Afghanistan that resulted in the deaths of more than a dozen fighters from both sides.

A first round of direct peace talks was held last summer in Pakistan, but the process quickly derailed after the announcement of the death of Taliban founder Mullah Omar.

The Taliban, toppled from power in a US-led invasion in 2001, has waged an armed campaign to overthrow the Afghan government and re-establish its rule.

The nearly 15-year conflict has killed thousands of people and strained the country's economy.

Last October, US President Barack Obama announced that thousands of US troops would remain in Afghanistan past 2016, keeping the current American force of 9,800 troops in place amid a surge in Taliban attacks.