"My friends, I will have an energy policy that we will be talking about, which will eliminate our dependence on oil from the Middle East that will prevent us from having ever to send our young men and women into conflict again in the Middle East," McCain said.
The expected GOP nominee sought to clarify his comments later, after his campaign plane landed in Phoenix. He said he didn't mean the U.S. went to war in Iraq five years ago over oil.
"No, no, I was talking about that we had fought the Gulf War for several reasons," McCain told reporters.
One reason was Saddam Hussein's invasion of Kuwait, he said.
"But also we didn't want him to have control over the oil, and that part of the world is critical to us because of our dependency on foreign oil, and it's more important than any other part of the world," he said.
"If the word `again' was misconstrued, I want us to remove our dependency on foreign oil for national security reasons, and that's all I mean," McCain said.
"The Congressional Record is very clear: I said we went to war in Iraq because of weapons of mass destruction," he said.
It was the second time in as many days that McCain had to clarify his comments. On Thursday, he backed off his assertion that pork-barrel spending led to last year's deadly bridge collapse in Minneapolis.
McCain is a staunch supporter of the Iraq war, although he criticizes the early handling of it by the Bush administration.
His support for the war has drawn attacks from the Democratic Party, and on Friday, McCain defended himself against television ads that accuse him of advocating a 100-year war in Iraq.
The ads, run by the Democratic National Committee and the liberal group MoveOn.org., tie McCain to President Bush and cite McCain's comments that there could be an American military presence in Iraq for 100 years.
"One hundred years in Iraq? And you thought no one could be worse than George Bush," an announcer says in the most recent ad, run by MoveOn.org.
McCain brought up the commercials in Denver, saying they are lies. He doesn't deny saying "100 years" in connection with U.S. military operations in Iraq. But he said he was clearly referring to a possible peacekeeping force and not a centurylong war, as critics imply.
"You have seen an ad campaign that is mounted against me that says I wanted to stay and fight in Iraq and fight for 100 years," McCain told about 300 people at the Robert E. Loup Jewish Community Center.
"My friends, it's a direct falsification, and I'm sorry that political campaigns have to deteriorate in this fashion," McCain said. "Because there's legitimate differences between myself and Senator Obama and Senator Clinton on what we should do in Iraq."
The Democratic presidential candidates want to set a date for withdrawal from Iraq, which McCain argues would lead to chaos and genocide in the Middle East.
"After we win the war in Iraq, and we are succeeding - and it's long and hard and tough, with enormous sacrifices - then I'm talking about a security arrangement that may or may not be the same kind of thing we had with Korea after the Korean war was over," he said.
At issue is McCain's answer, in January, to a question about Bush's theory that troops could be in Iraq for 50 years.
McCain said: "Maybe 100. As long as Americans are not being injured or harmed or wounded or killed, that'd be fine with me, and I hope it would be fine with you, if we maintain a presence in a very volatile part of the world where al-Qaida is training, recruiting, equipping and motivating people every single day."
