U.S. presumptive Republican presidential candidate John McCain vowed on Thursday, for the first time, to bring home most troops to Iraq by 2013 after the U.S. wins the war by his watch.

"By January 2013, America has welcomed home most of the servicemen and women who have sacrificed terribly so that America might be secure in her freedom," McCain said in a speech in Columbus, Ohio.

McCain noted that by 2013 the U.S. troops still in Iraq would not play a direct combat role.

The 71-year-old Arizona Senator said that his administration would lead to termination of the al-Qaida leader, Osama bin Laden, and diminution of threat from the Taliban in Afghanistan.

"The increase in actionable intelligence that the counterinsurgency produced led to the capture or death of Osama bin Laden, and his chief lieutenants," he said.

He also released a plan during the speech on decades-long presence of U.S. troops that is aimed at maintaining stability in the region just like its military presence in Japan, South Korea and Germany.

However, McCain conceded that he cannot make the change alone but should outline a specific governing style to show the accomplishments it can achieve.

"There is a time to campaign, and a time to govern," he said. "If I'm elected president, the era of the permanent campaign will end; the era of problem solving will begin."

McCain's Democratic rivals, Hillary Rodham Clinton and Barack Obama, both vowed to start to withdraw combat troops as soon as they are elected and accused the Republican government of dragging the country's economy with ballooning war costs.

According to a poll by Washington Post-ABC News in March, nearly two-thirds Americans said that the war was not worth fighting and fewer than half think that the United States is making significant progress restoring civil order in Iraq.

The Iraq war, launched on March 20, 2003, has consumed U.S. taxpayers billions of U.S. dollars and nearly 4,000 U.S. troops' lives. It was also cited as the main reason for the country to suffer from the economic woes and the deteriorated international image.

(Xinhua News Agency May 16, 2008)