OTTAWA - Prime Minister Stephen Harper says it's up to the government of Afghanistan to decide if it wants to embark on a negotiated peace with the Taliban.

The Conservative leader says Afghan President Hamid Karzai's government has been willing to talk to the Taliban, but under certain conditions.

"President (Hamid) Karzai has always been open to talking to the Taliban at various levels, provided these people are willing to participate in the democratic and constitutional process," he said Monday while campaigning for the Oct. 14 federal election.

"That's very different than simply throwing down arms and letting the Taliban take over the country -- which is certainly not what we're proposing."

Questions about peace talks arose as it emerged that a former high-level Taliban official met last month in Saudi Arabia with representatives of the Taliban, the Afghan government and a powerful Afghan warlord.

And they come after Britain's senior military commander in Afghanistan said the war cannot be won and can only be resolved through peace talks that involve the Taliban.

But Abdul Salam Zaeef -- the Taliban's former ambassador to Pakistan -- said the meeting in Saudi Arabia could not be construed as a peace negotiation.

Zaeef said he was invited by Saudi King Abdullah to share the Iftar meal with him one night. The meal is held each night during the Muslim holy month of Ramadan to break the daily fast.

"This is not new, it's a kind of a guest celebration," Zaeef told The Associated Press.

Karzai's government has long encouraged the insurgents to lay down their arms and accept the country's constitution. But the Taliban leadership has largely rebuffed repeated overtures from Afghan officials aimed at ending the country's six-year-old conflict.

U.S. officials have not indicated they are ready for any contacts with high-level Taliban leaders, though U.S. officials do encourage fighters to lay down arms and join the government's reconciliation program.

Last week, Karzai said he has repeatedly asked Saudi Arabia's king to facilitate peace talks with the Taliban. Karzai said Afghan officials have travelled to Saudi Arabia and Pakistan to that end but there have not been any negotiations so far.

Over the weekend, NDP Leader Jack Layton seized on the comments made by the British military commander as validation of his policy in Afghanistan.

Layton wants Canada's troops out of the war-ravaged country.

Liberal MP Bob Rae attacked Layton's position on Monday as a threat to Canada's military alliances.

In a speech at a Halifax restaurant, Rae said Layton is ignoring the military commander's comments that state NATO troops need to remain in the region, allowing diplomacy and development to occur.

The former Ontario premier says that part of the message is "directly contrary" to the NDP position that Canada should withdraw troops.

"He (Layton) suggested that if we pulled our troops out instantly, that there would somehow be a diplomatic job for Canada to do. ... It's a complete and total fantasy," said Rae, the party's foreign affairs critic.

Rae said Canada can't simply abandon its promises to its allies and to the government of Afghanistan.

"His view underestimates the fact that Canada's membership in NATO carries with it obligations. You can't just come and go. You can't just say we're here today and gone tomorrow," he said.

"Our aid work and our assistance in training the Afghan army and the police can't be done without having troops on the ground to do their job."