Hamid Karzai, Afghanistan's president, has called on the Taliban and other local fighters to vote in landmark elections scheduled for August.

At a press conference on Saturday, Karzai said all eligible Afghans should register and cast their ballots in the August 20 presidential and provincial council elections.

"It is also my wish that our Taliban brothers and all other Afghans who are not in Afghanistan for various reasons and are standing in opposition ... I request them again and again to renounce violence, not only on the election day but forever," Karzai said.

Forty-one candidates are running for president and a recent poll showed Karzai with a big lead over his opponents.

Karzai also extended his appeal to Taliban fighters based in Pakistan, where many of them fled following the 2001 US-led invasion of Afghanistan.

While the Taliban and other fighters have not announced direct plans to target polls, they have told Afghans to boycott the elections.

Two of the more than 3,000 candidates for the provincial councils have been murdered in recent weeks.

Intimidation fears

The US and other allies have pledged thousands of extra soldiers to protect polling stations and are bankrolling the elections at a cost of $220m.

Last week, Nato's senior military commander warned that fighters could block transport routes and use intimidation to interfere with the elections.

"I'm sure there will be attempts by the insurgents, the Taliban, to interfere with the polling," John Craddock, Nato's supreme allied commander in Europe, said at his headquarters in Belgium.

Karzai urged fighters to contribute to leading the country towards stability through elections and called on candidates to prioritise national unity.

"We can try for peace through elections, and through elections we can bring development to this country," he said.

Karzai also warned against "interference" by any country, which he said might want to influence the outcome of the elections.