Kabul - The outgoing NATO Secretary General Jaap de Hoop Scheffer arrived in Kabul Wednesday for talks with Afghan officials - as three soldiers serving under the banner of NATO-led international forces were killed in a blast.

"We are not here to achieve any form of military victory," Scheffer told a press conference after meeting with Afghan President Hamid Karzai in his fortified presidential palace.

"We are here, of course, because we simply can not afford extremism to take the upper hand," he said in the joint press conference with Karzai on Wednesday evening.

"There are many enemies of Afghanistan who don't want to see this country develop, do not want to see the Afghan citizen live in security and peace, and we have joined hands to prevent that from happening," he said.

Scheffer also promised to deploy 8,000 to 10,000 extra soldiers on temporary basis before the polling day in August's presidential election.

Karzai called Scheffer a friend of Afghanistan and thanked the alliance for providing security for his war-torn country since the ouster of Taliban regime in late 2001.

During his final visit as the alliance's chief, Scheffer was scheduled to hold separate talks on Thursday with former finance minister, Ashraf Ghani and former foreign minister, Dr Abdullah Abdullah.

Both men are frontrunners in the August 20 presidential election.

Ghani and Abdullah are widely seen as serious contenders to unseat President Karzai, who has ruled the country since after the ouster of the Taliban regime in late 2001.

Despite losing popularity at home and abroad, Karzai, who is accused of presiding over a largely-corrupt government, is expected by many observers to win the election.

A two-month campaign for the presidential candidates began on Tuesday, but many of the candidates have already voiced concerns that insecurity in several districts in southern and eastern regions would not allow them to campaign in rural areas.

Denmark's Prime Minister, Anders Fogh Rasmussen, is to succeed Scheffer, as of August 1.

Meanwhile, three NATO-led International Security Assistance Force (ISAF) soldiers were killed on Wednesday in the volatile southern region, ISAF said in a statement, but did not reveal the nationalities of the soldiers.

Around 140 international soldiers with more than half of them US troops have been killed in Afghanistan so far this year. Nearly foreign 300 soldiers died in Afghanistan conflict last year, which marked it the deadliest year for the foreign troops in the country.

More than 70,000 international soldiers from 42 countries are stationed in Afghanistan. 21,000 additional US soldiers are scheduled to arrive in the country by summer to help provide security for the upcoming presidential elections in August.(dpa)