U.S. Defense Secretary Leon Panetta says the war in Afghanistan cannot be determined by opinion polls.

Speaking to reporters in the Canadian capital, Ottawa, where he attended talks with his Canadian and Mexican counterparts on strengthening security ties, Panetta said “we cannot fight wars by polls… If we do that, we are in deep trouble.”

He said “We have to operate based on what we believe is the best strategy to achieve the mission that we have embarked on. And the mission is to safeguard our country by insuring that the Taliban and al-Qaida never again find a safe haven in Afghanistan.”

Panetta made the comments a day after a New York Times/CBS poll found that public support for the decade-long war had dropped sharply. Sixty-nine percent of those questioned said they believe the United States should not be in Afghanistan and a growing number of people want President Barack Obama to speed up the pullout of combat troops from the war-torn country.

And while anti-American sentiment in Afghanistan is on the rise following a period of turmoil in the country, many Afghans also fear that a sudden pullout of foreign troops could plunge the country into an all-out civil war, involving the Afghan security forces, the Taliban and other ethnic and tribal factions.

The killing of 17 Afghan civilians allegedly by a U.S. soldier, the recent inadvertent burning of Qurans at a U.S. military base near Kabul and numerous attacks on international forces by their Afghan counterparts, have increased tensions and undermined trust between the two sides.

The Quran burning incident sparked a week of violent anti-American protests and attacks on coalition forces, while the Taliban suspended peace talks with the U.S. being held in Qatar.

According to the U.S. Defense Department, at least 80 coalition troops have been killed by Afghan security forces since May 2007, three of them on Monday.

A member of the Afghan parliament's defense committee said neither the U.S. nor Afghanistan should make long-term policy decision based on temporarily inflamed tensions between the two countries. She said both sides need to stay focused on what unites them — the need to fight al-Qaida and other radical Islamic militant groups, and to ensure regional stability.