Updated

]Taliban leader Mullah Omar on Tuesday dismissed elections due in Afghanistan next year as "a waste of time", posing a challenge to international efforts to ensure a credible poll.

The participation of the Pashtun ethnic group -- from whom the Taliban get most of their support -- is seen as essential to the success of the presidential election, scheduled for April 5.

The vote will be an important test of Afghanistan's progress since the fall of the Taliban regime in 2001. The United States and other foreign donors say the poll is crucial for the country's future after NATO-led combat troops withdraw next year.

"As to the deceiving drama under the name of elections 2014, our pious people will not tire themselves out, nor will they participate in it," Omar said.

"Selection, de facto, takes place in Washington... participation in such elections is only a waste of time, nothing more."

In previous elections, the Taliban called on Afghans to boycott voting, sent fighters to block roads to polling stations and targeted candidates and activists.

Pashtuns often complain they are unable to vote due to poor security and Taliban threats, pointing to Pashtun-majority Ghazni province where ethnic Hazara candidates won all 11 seats in 2010 parliamentary elections.

The reclusive one-eyed supremo issued a lengthy statement on the Internet ahead of Eid celebrations due to begin in Afghanistan on Thursday to mark the end of the holy month of Ramadan.

Omar offered glimmers of hope for peace after 12 years of fighting, saying that the Taliban -- who sheltered Al-Qaeda during their harsh rule of Afghanistan from 1996-2001 -- did not seek a return to absolute power.

"(The Taliban) does not think of monopolising power," he said. "Rather we believe in reaching understanding with the Afghans regarding an Afghan-inclusive government based on Islamic principles."

Omar's message also said "nor (will) we allow anyone to harm others from our soil" -- a vow in line with US demands that the country does not return to being a safe haven for global militancy.

During their rule, the Taliban banned girls from going to school, outlawed television, music and the cinema, and forced women wear the all-covering burqa.

But Omar, who presided over the Islamist regime, signalled a partial change to their extreme interpretation of sharia law.

"To protect ourselves from scarcity and hardships, our young generations should arm themselves with religious and modern educations because modern education is a fundamental need of every society," he said.

Nearly 70,000 US troops and 30,000 soldiers from other countries are still deployed in Afghanistan, fighting the Taliban and training up the national army and police to take on the insurgents.

All foreign combat troops will leave Afghanistan by the end of 2014, with many Afghans fearing they face a new era of turmoil after decades of war since the Soviet occupation in 1979.

The US is considering leaving a residual military force in the country to aid stability, target Al-Qaeda fighters and further strengthen the security forces.

But Omar railed against any foreign troops staying in Afghanistan, saying that "the occupying countries should learn from the bitter experiences of the past 12 years.

"They should not try their fate once more by prolonging the occupation".

Initial attempts to start peace talks with the Taliban collapsed in June when a new office in Qatar for the insurgents enraged President Hamid Karzai, because it was styled as an embassy for a government in exile.

Omar said the office proved the Taliban "is showing honesty and commitment to resolve problems of its oppressed people... but the invaders and their allies are creating obstacles".

Violence has continued to rage across much of Afghanistan as NATO troops begin their pullout and Afghan troops increasingly move to the frontlines.

"The current jihad in Afghanistan is continuing with great success," Omar, who has often been rumoured to be dead, said. "Many areas of the country have been liberated from the grips of the invading usurpers."

US special envoy James Dobbins said in Kabul on Thursday that the elections to succeed Karzai were "the most important event that is going to shape Afghanistan's future.

"If the election goes well and produces a result that is widely accepted in the country, most other of Afghanistan's challenges are going to be satisfactorily met."