U.S. Defense Secretary Leon Panetta says opinion polls cannot determine the war in Afghanistan.

Panetta, attending security talks in Ottawa with Canadian and Mexican defense chiefs, says the United States would be in “deep trouble” if it fought wars by surveys.

He says the Pentagon has to operate based on what it believes is the best strategy to achieve the mission. He says the mission in Afghanistan is to safeguard U.S. security by ensuring the Taliban and al-Qaida never again find a safe haven in Afghanistan.

A New York Times/CBS News polls released Monday finds that public support for the decade-long war has dropped sharply. Sixty-nine percent of those questioned said they believe the United States should not be in Afghanistan. The survey shows that a growing number of people want President Barack Obama to speed up the pullout of combat troops from the war-torn country.

But Afghans fear that a sudden withdrawal of foreign troops could plunge the country into an all-out civil war between Afghan security forces, the Taliban and other ethnic and tribal factions.

NATO says the top commander of an al-Qaida-linked militant network was killed Monday in a firelight with coalition forces near the Afghan border with Turkmenistan.

Makhdum Nursat headed the Islamic Movement of Obeisant. NATO commanders say he was wanted for attacking coalition forces in northern Afghanistan.