WASHINGTON — Unveiling a revised strategy on Afghanistan, John McCain called for sending thousands more troops there and clashed with Barack Obama about their often divergent foreign policy visions.

McCain, a Republican senator from Arizona, proposed deploying three new brigades and doubling the Afghan armed forces. McCain said the plan is based on President Bush's escalation of troops in Iraq that Obama opposed for that war.

"It is precisely the success of the surge in Iraq that shows us the way to succeed in Afghanistan," McCain said.

McCain has long resisted proposals to send more U.S. troops to Afghanistan.

Obama, an Illinois senator, had already pledged to send two more combat brigades to Afghanistan. He described Iraq as a distraction that has sapped money and attention from vital national security interests. "I will end this (Iraq) war as president," Obama said.

McCain focused on Afghanis-tan in remarks that had initially been scheduled for tomorrow. He had planned instead to discuss the economy at a New Mexico event — a sign behind him read Jobs For America.

"I know how to win wars," he said there.

Asked later where new troops for Afghanistan would come from, McCain said, "we need to work that out," and that it would involve "greater participation from our NATO allies."

Meanwhile, Obama outlined his national security priorities just days before a trip to Europe and the Middle East. His address before a Washington audience of more than 600 academics attempted to dispel any suggestions that he has been vacillating on his plans to wind down U.S. military involvement in Iraq.

Ending the Iraq war and reviving the priority of the conflict in Afghanistan are two of the five goals Obama laid out in a speech he titled "A New Strategy for a New World." The others: protecting nuclear weapons materials around the globe; developing energy alternatives to Mideast oil; and repairing alliances frayed during the Bush administration. Obama emphasized the importance of diplomacy and repeated his willingness to meet with leaders hostile to the United States.

Obama faulted McCain for failing to see the problems in the Iraq war when he supported the invasion back in 2003. Saying that Iraq "had absolutely nothing to do with the 9/11 attacks," Obama criticized that war as a wasteful detour from the battle against al-Qaida. He chided McCain for saying earlier this year that "Afghanistan is not in trouble because of our diversion to Iraq."

For his part, McCain noted that Obama has never "set foot" in Afghanistan, and criticized him for proposing plans for Iraq and Afghanistan before his upcoming trip to those countries. (Obama also was part of a congressional delegation to Iraq in 2006.)

"Fact-finding missions usually work best the other way around," he said. "First you assess the facts on the ground, then you present a new strategy."