KABUL, Afghanistan - President Hamid Karzai offered Sunday to provide security for the Taliban's reclusive leader Mullah Omar if he agrees to enter peace talks, and suggested that the United States and other western countries could leave the country or oust him if they disagree.

Karzai's comments come as international political and military leaders are increasingly mulling whether negotiating with the Taliban is necessary as the insurgency gains sway in large areas of Afghanistan.

Karzai has long supported drawing the militia into the political mainstream on the condition that they accept the country's constitution.

"If I say I want protection for Omar, the international community has two choices, remove me or leave if they disagree," Karzai said in an hourlong news conference in Kabul.

"If I am removed in the cause of peace for Afghanistan by force by them, then I will be very happy. If they disagree, they can leave. But we are not in that stage yet," Karzai said.

Omar headed the government toppled by the U.S.-led invasion in 2001. Since then, he has been in hiding but is believed to be running the insurgency.

Previously, Karzai has said that Omar lives in neighbouring Pakistan, an allegation dismissed by Pakistani officials.

Seven years after the invasion, record levels of violence are afflicting Afghanistan, where the number of insurgent attacks are up by 30 per cent compared to 2007. The Taliban are present in large parts of Afghanistan's south and east and are increasingly encroaching on Kabul, the capital.

In September, Taliban members met with Afghan and Pakistani officials during a dinner hosted by Saudi Arabia's king, but there were no concrete results from the meeting.

"If I hear from (Mullah Omar) that he is willing to come to Afghanistan or to negotiate for peace and for the well-being of the Afghans so that our children are not killed anymore, I as a president of Afghanistan will go to any length to provide protection," Karzai said.

Omar has not directly responded to these calls, but spokesmen associated with the Taliban have previously said their participation in any talks depends on the withdrawal of U.S. and other foreign troops from the country.

Karzai dismissed that, saying foreign troops are necessary for Afghanistan's security.

Meanwhile, Pakistan temporarily barred oil tankers and container trucks from a key passageway to Afghanistan, threatening a critical supply route for U.S. and NATO troops on Sunday and raising more fears about security in the militant-plagued border region.

Confirmation of the suspension came as U.S.-led coalition troops reported killing 30 insurgents in fighting in southern Afghanistan and detaining two militant leaders -- both in provinces near Pakistan's lawless border.

Al Qaeda and Taliban fighters are behind much of the escalating violence along the lengthy, porous Afghan-Pakistan border, and both countries have traded accusations that the other was not doing enough to keep militants out from its side.

There was no major announcement of the ban, and it was unclear how strictly it had been enforced in the past week. News of the ban filtered into local media over the weekend.