(AFP) Prime Minister Dr Mahathir Mohamad has denounced a religious ruling calling for the boycott of US products in retaliation for its bombing campaign in Afghanistan.

"We should not be emotional, we should think practically, things that we can do, we do, things that we cannot, we don't talk about it," Mahathir was quoted as saying by Bernama news agency.

"It's unfair to ask the government to boycott (American goods), we do it on our own, things that we don't need, we don't use," the 75-year-old premier added.

An association of Islamic clerics on Sunday condemned the US bombing of Afghanistan, calling it an act of aggression against Islam and urging Muslims to wage a holy war.

A 16-point resolution issued after a one-day meeting urged Muslims to boycott US products and services and demanded an immediate withdrawal of US and British troops from Afghanistan.

Mahathir said the ruling was difficult to implement, saying American-made Boeing aircraft was used to fly Malaysian pilgrims to Mecca.