KABUL, May 4 Afghan President Hamid Karzai officially registered on Monday to stand for re-election, solidifying his support by naming two prominent members of the Tajik and Hazara minorities as running mates.

“I have taken this decision for the welfare and interest of the people of Afghanistan,” Mr Karzai, who has led Afghanistan since 2001, said of his decision to seek another term.

Meanwhile, the United Nations and international diplomats in Kabul strongly opposed Mr Karzai's choice of a warlord and alleged rights abuser as running mate.

As the Aug 20 election draws closer, Mr Karzai appears to be in an all but unassailable position, with the opposition struggling to name a contender with a broad enough base of support to win.

The Afghan president spoke to reporters outside the offices of the Independent Election Commission in Kabul, flanked by his running mates, shortly after signing his registration form.

“We will endeavour to bring security, peace and tranquillity to Afghanistan,” he said. “As in the past, we will make mistakes ... but we will be in the service of the Afghan nation.”

In a sign of the opposition's difficulties, one of Karzai's running mates for two vice presidential posts, former vice-president Mohammad Qasim Fahim, was a founder and leader of an opposition group until he quit to back the president this month.

For the second vice presidential post, Mr Karzai retained Karim Khalili, who has occupied the post since 2004. Mr Karzai is a Pashtun from the country's largest ethnic group, while Fahim and Khalili represent the second- and third-largest groups, the Tajiks and Hazaras, giving President Karzai's ticket ethnic balance.

Other possible rivals include former foreign minister Abdullah Abdullah, former finance ministers Ashraf Ghani and Anwar-ul-Haq Ahadi, and even possibly Afghan-born former US envoy to Afghanistan, Iraq and the United Nations, Zalmay Khalilzad.

Most are technocrats with careers abroad and narrow political bases inside Afghanistan. They have until May 8 to register.

The choice of Qasim Fahim, a former leader of a guerrilla faction, could raise eyebrows among international donors who would like to see Karzai limit the influence of powerful ex-armed chieftains.

“You want a team that can move forward,” said one senior international diplomat in Kabul. “Now they risk getting a team that will be seen as moving backwards, both in Afghanistan and even overseas.”

UN special representative Kai Eide believed Karzai's choice of Fahim could cost him international and Afghan support, the diplomat close to the United Nations told reporters on condition of anonymity.—Agencies