John McCain on Monday said he is proud of his military service and said recent critical comments by Barack Obama supporter Wes Clark were "unnecessary," as Obama repudiated political attacks on military service and criticized a MoveOn.org newspaper ad that riled lawmakers last year.

A day earlier, Clark -- a former NATO commander under President Clinton who now advises Obama -- dismissed the value of McCain's military record as a qualification for the presidency saying, "I don’t think riding in a fighter plane and getting shot down is a qualification to be president.”

Since Sunday, Clark's remarks had spurred a flurry of counterpunches between campaign surrogates, but McCain's appearance Monday was his first time to speak publicly about Clark's words.

"That kind of thing is unnecessary. I am proud of my record of service, and I have plenty of friends and leaders who will attest to that," McCain said, adding those sorts of attacks don't "reduce the price of a gallon of gas by one penny" or help struggling Americans keep their jobs or homes.

McCain was speaking to reporters in Harrisburg, Pa., where he had toured Turbine Airfoil Design plant to bolster his economic message.

But almost simultaneously during a speech on patriotism in Independence, Mo., Obama told an audience that McCain's patriotism was clear, and alluded to Clark's comments by calling for a cease to politically motivated attacks on military service.

"For those like John McCain who have endured physical torment in service to our country -- no further proof of such sacrifice is necessary. And let me also add that no one should ever devalue that service, especially for the sake of a political campaign, and that goes for supporters on both sides," Obama said.

And if the reference was not clear enough, Obama campaign spokesman Bill Burton issued a separate statement regarding Clark's comments.

"As he's said many times before, Senator Obama honors and respects Senator McCain's service, and of course he rejects yesterday's statement by General Clark," Burton said.

Obama has been attacked for not wearing an American flag lapel pin and for allegedly failing to place his hand over his heart during the pledge of allegiance to the flag. He challenged his critics in a forceful speech in the aptly named city of Independence, Missouri, as he kicked off a campaign week that includes the July 4 U.S. holiday celebrating independence from Britain.

Obama, baptized a Christian two decades ago, also has fought persistent Internet rumors that he is Muslim.

"I have found, for the first time, my patriotism challenged -- at times as a result of my own carelessness, more often as a result of the desire by some to score political points and raise fears about who I am and what I stand for," he said before a crowd of a few hundred people at the Truman Memorial Building in President Harry Truman's hometown.

In his chat with reporters, McCain demurred when he was given the chance to question, or put down questions about Obama's patriotism.

When a reporter asked the Arizona Republican, "do you question at all his patriotism," McCain said:

"I think that Senator Obama is a great American success story. I think his family is. I think he's someone who is admired and respected throughout this country and the world. I think our differences are how we intend to move forward in conducting the affairs of this country. We have very different views, and very different positions."

McCain continued :"I think all Americans are proud of Senator Obama and what he's been able to accomplish -- he and his entire family. ... And I think it's living proof of some of the great, greatness of America."

McCain also reiterated a point that he made at a fundraiser on Saturday, that Obama can't be trusted.

"I certainly don't think he can be trusted in the case of a very, very important factor in the conduct of our campaigns. He said, he repeated in writing and verbally that he would take public financing in the general election if I did. ... And obviously, he reversed his position on that issue," McCain said.

Obama's campaign contends Obama never committed to maintain public financing, but rather committed only to talking to McCain's campaign about taking public financing. McCain disputes the Obama campaign took that step either.

In the Sunday interview, Clark also said he didn't believe McCain's military service -- including his capture and imprisonment in Vietnam, qualified him to be president

"He has been a voice on the Senate Armed Services Committee. And he has traveled all over the world. But he hasn’t held executive responsibility," Clark said.

When asked by host Bob Schieffer how he came to describe McCain as "untested and untried," Clark said it was "because in the matters of national security policy-making, it’s a matter of understanding risk. It's a matter of gauging your opponents and it's a matter of being held accountable. John McCain's never done any of that in his official positions," adding, "He hasn't made the calls."

Moving On?

In his speech, Obama also appeared to refer to a strongly worded -- and highly criticized advertisement placed last year in The New York Times by the liberal advocacy group MoveOn. The advertisement, placed on the day Multinational Forces-Iraq commander Gen. David Petraeus delivered a pivotal report to Congress, was titled: "General Betray Us?"

Obama said divisions from the 1950s and '60s persist, and "All too often, our politics still seems trapped in these old, threadbare arguments, a fact most evident during our recent debates about the war in Iraq, when those who opposed administration policy were tagged by some as unpatriotic, and a general providing his best counsel on how to move forward in Iraq was accused of betrayal.

"Given the enormous challenges that lie before us, we can no longer afford these sorts of divisions."

In a Sept. 20, 2007, vote, the Senate passed a resolution "to specifically repudiate the unwarranted personal attack on General Petraeus by the liberal activist group Moveon.org."

McCain has criticized Obama for not supporting the amendment. McCain voted for the amendment, while Obama did not vote. The amendment passed the Senate 72-25.

Click here to see how your senator voted on the resolution.

Obama voted earlier that day on a separate amendment, which "strongly" condemned "all attacks on honor, integrity, and patriotism of any individual who is serving or has served honorably in the United Stats Armed Forces, by any person or organization." That bill did not refer to MoveOn by name, but called the ad an "unwarranted personal attack." It also referred to attacks on Democrats, including Massachusetts Sen. John Kerry and former Georgia Sen. Max Cleland.

The Associated Press contributed to this report.