WASHINGTON — In a stepped-up defense of the Iraq war, Senator McCain is accusing Democrats of seeking political advantages over military victory in their efforts to force an end to the war while also trying to pit the party’s leading presidential candidates against each other.

Delivering a major war speech at the Virginia Military Institute yesterday, the Arizona Republican singled out Senator Obama for subtle praise, saying Democrats should follow his “advice” to send a funding bill without restrictions to President Bush once he vetoes, as promised, a measure that includes timetables for American troop withdrawal.

“I hope Democrats in Congress will heed the advice of one of their leading candidates for president, Senator Obama, and immediately pass a new bill to provide support for our troops in Iraq without substituting their partisan interests for those of our troops and our country,” Mr. McCain said, in his only mention of a Democratic opponent by name.

The remark was an apparent reference to comments Mr. Obama had made last week suggesting lawmakers would not “play chicken” with troops on the ground and were unlikely to vote to cut off funding for the war. It was seen by some as an early admission of defeat in the Democratic standoff with the president.

Mr. Obama’s campaign dashed off a statement even before Mr. McCain finished his speech in which the Illinois senator ridiculed Mr. McCain’s claims that the American strategy is making progress in Iraq. “Progress in Iraq cannot be measured by the same ideological fantasies that got us into this war,” Mr. Obama said.

Appearing later yesterday on CNN, he said Mr. McCain “was misquoting me a little bit.”

“I have enormous respect for John McCain, but I think he is flat wrong on this issue,” Mr. Obama said of his stance on Iraq. “And he’s been wrong on this for some time.”

Like Senator Clinton — his top rival for the Democratic nomination — Mr. Obama has faced pressure from all sides on the war issue. Although he has repeatedly pointed out that he opposed the Iraq war “from the start,” he has not been willing to go as far as some of his rivals in urging an immediate cutting off of funds and withdrawal of troops. In a speech last night in Iowa, another Democratic candidate, Senator Dodd of Connecticut, challenged the other contenders to support a bill offered by the Senate majority leader, Harry Reid of Nevada, and Senator Feingold of Wisconsin, that would impose a firmer timetable. Mr. Obama said on CNN he was not “prepared to say I am going to cut off funding.”

On the Republican side, Mr. McCain used yesterday’s speech to make his most extensive argument yet for an American effort to win the war in Iraq. Like Mr. Bush, he cast the battle as the key front in the war on terror, and he said his visit to the country last week gave him “cause for cautious optimism.”

He accused Democrats who are advocating withdrawal and insisting that funding be tied to a timetable of “small politics.”

“It may appear to be the easier course of action, but it is a much more reckless one, and it does them no credit even if it gives them an advantage in the next election,” Mr. McCain said.

Once considered a front-runner for the Republican nomination, Mr. McCain has struggled in recent months, partly due to his steadfast and vocal support of the war and the president’s decision to send additional troops to Iraq.

At least one top supporter was sticking by him yesterday.

“At the moment, does it appear to be the unpopular position? Yes. But I believe he’s right,” a national co-chairman of Mr. McCain’s campaign, Lewis Eisenberg, said.