KABUL (Reuters) -- Taliban chief Mullah Mohammad Omar has urged Western forces to take a "golden opportunity" to leave Afghanistan before thousands of their troops were killed in the Islamist group's renewed insurgency.
Omar, believed by Western intelligence to be hiding in the mountainous border area between Afghanistan and Pakistan, also said a planned increase in U.S. troops would fail to curb violence and would instead fuel the insurgency.
"I would like to remind the illegal invaders who have invaded our defenseless and oppressed people that it is a golden opportunity for you at present to hammer out an exit strategy for your forces," Omar said on the day of Eid al-Adha, the Islamic festival of sacrifice, in his yearly message.
"The current armed clashes which now number into tens, will spiral up to hundreds of armed clashes. Your current casualties of hundreds will jack up in to the thousands," he added in an e-mailed statement.
Afghanistan has seen the worst bloodshed this year since U.S.-led and Afghan forces toppled the Taliban in 2001, with at least 4,000 people killed in the first half of 2008, about a third of them civilians, and some 140 Taliban suicide bombs.
Civilian casualties caused by foreign air strikes have become the biggest source of tension between President Hamid Karzai and his Western backers. Omar said any increase in civilian deaths would help boost the Taliban's insurgency.
"The more you destroy our people's houses, the more you martyr our people, the more you will face the wrathful reaction of our mujahedin," he said.
Taliban suicide attacks killed at least 200 civilians last year, undermining public faith in the ability of the government and international troops to bring security to a country that has seen more or less continual war for the last 30 years.
The United States is sending an extra 3,000 troops to Afghanistan in January and is considering plans to dispatch up to 20,000 more in the next 12 to 18 months.
"The rationale will not seem cogent even to your own people, and because of your blind bombardments, which usually result in the murder of defenseless Muslims, men, women, and children, you will not escape the wrath of the Islamic Ummah," he said.
Omar also blamed the global financial crisis on the United States and said it had left a "negative impact on the globe," resulting in "the collective duty of all" to derail what he called "this war-mongering trend."