Kabul - In a clear sign of discord between Afghan government and its main backer, President Hamid Karzai said Wednesday that he has come under pressure from Washington for his criticism over civilian casualties caused by the US and NATO military troops.

"For along time now we and the Americans have discord in our opinions regarding the civilian casualties, search of Afghan homes and the arrest of Afghans and therefore there are tensions in our relations," Karzai told a joint press conference with visiting UN Secretary-General Ban Ki-moon.

"Our demand is very clear: we want an end to search of Afghan homes, entering to Afghan homes and their arrests," Karzai said. "But it is natural that they in return put pressure on us so that we keep quiet and retract our claims, which is not possible."

Thousands of Afghan civilians have been killed in the fight between the Taliban insurgents and Afghan and international forces since the ouster of Taliban regime in late 2001.

More than 2,100 civilians were killed as a result of armed conflict in 2008, an increase of about 40 per cent from 2007, according to the latest UN estimates.

Karzai's comments came amid increasing criticisms by disillusioned Western officials. Several US military and civilian officials have faulted Karzai for being unable to tackle the endemic corruption in his administration and the narcotics trade.

US Secretary of State Hillary Clinton described Afghanistan last month as a "narcotics state" and its government highly "corrupt." Other senior US and other Western officials have also expressed their frustrations with Karzai and have repeatedly called him "weak."

In an opinion piece published by The Washington Post last month, NATO Secretary General Jaap de Hoop Scheffer wrote, "Afghans need a government that deserves their loyalty and trust."

But Karzai, who is facing reelection later this year, dismissed the criticism Wednesday as distractions by the US and NATO officials to counter his demands for ending the civilian deaths.

The president said he had been urging the alliance "in a humble way to stop their oppression on our people" since 2006, "but unfortunately in return they attacked us through their media."

"I hope instead of getting angry at us and putting pressure on us, they should sit down with us so that we could work together to reduce the civilian casualties," he said

"Afghanistan and its people will not stop their demands. We want the civilian casualties, search of homes, and arrest of our people to be stopped."

UN chief Ban also expressed his concern over civilian deaths, saying, "I fully share the concerns and frustration President Karzai has endured because of many tragic incidents, where civilian people were killed in the course of military operations in fighting against terrorism."

"On many occasions I have expressed strong concerns that while conducting the military operations, they must ensure not to have all these civilian casualties occur," Ban said.

Karzai's recent verbal attacks on NATO could strain relations between his government and his Western allies.

A tough fight is expected in Afghanistan this spring as the US is planning to send up to 30,000 extra troops to join the already 70,000 international forces deployed to the country from 41 nations.

"There is one condition in every partnership, which is it has two sides, so we are one side of this partnership, therefore our points of view should also be taken into consideration," Karzai added. (dpa)