WASHINGTON — Senator McCain is going further than President Bush or the Democrats vying for the White House in identifying Russia as a rival and not an ally.

In a major speech on foreign policy, Mr. McCain said the group of eight industrialized nations must include Brazil and India but exclude Russia, a state he called “revanchist.” He rejected Russian threats against nations aspiring to join the North Atlantic Treaty Organization from the “Baltic to the Black Sea,” a direct reference to Ukraine, whose membership in NATO has so worried Moscow that the Kremlin has threatened to aim its nuclear arsenal at Kiev if it joined the alliance.

President Bush is expected to meet with the Russian president, Vladimir Putin, next week after a NATO summit. The meeting will likely be the last between the two men before Dmitry Medvedev is sworn in as president on May 7. Mr. Bush supported opening the process for both Ukraine and Georgia to apply for NATO membership, but Germany has indicated it is against raising the issue at this time.

“Rather than tolerate Russia’s nuclear blackmail or cyber attacks, Western nations should make clear that the solidarity of NATO, from the Baltic to the Black Sea, is indivisible and that the organization’s doors remain open to all democracies committed to the defense of freedom,” Mr. McCain said yesterday.

The national security adviser for the McCain campaign, Randy Scheunemann, said that the Arizona senator did not seek “confrontation” in all arenas with Moscow. Mr. McCain did say he favored a nuclear arms reduction, a policy pursued by President Bush before the attacks of September 11, 2001, and a policy that would be pursued in cooperation with Russia. But Mr. Scheunemann added, “We need to be much more clear with Russia when we disagree with them.”

Specifically, Mr. Scheunemann said Mr. McCain was referring to an alleged Russian-led cyber attack on Estonia earlier this month, when Estonian government and private Web sites were frozen in response to a decision to remove a monument to the Red Army in the Estonian capital, Tallin. Estonia’s president, Toomas Hendrik Ilves, on March 12 asked the European Union to make cyber attacks a class of crimes in response to what he said was Russia’s retaliation for removing the Red Army monument.

Mr. McCain has in the past called on Russia’s removal from the Group of Eight industrialized nations and he has also supported the expansion of NATO, but the harsh words from the senator also distinguish him from his Democratic rivals, who have criticized Russia’s squelching of democracy at home and aggressive behavior towards its neighbors but have offered few concrete policy recommendations to address the issue. An official who dealt with Russia during the Clinton administration, James Goldgeier, said Mr. McCain’s view on NATO was correct, but that it would be difficult to achieve his goal of removing Moscow from the G-8.

“It is a group that is supposed to be for democracies,” Mr. Goldgeier said. “When Russia was invited, there was a belief that Russia was going in the direction of democracy. I don’t think it will be easy now to kick Russia out of the G-8. I am reminded of Bill Clinton in 1992 bashing George H. W. Bush on China, but when he gets into office he has to deal with China. It’s different when you are the president,” he said.

In other points in the speech, Mr. McCain contrasted his own personal experience and hatred of war with the necessity of staying in Iraq to prevent a broader one. “Only a fool or a fraud sentimentalizes the merciless reality of war. However heady the appeal of a call to arms, however just the cause, we should still shed a tear for all that is lost when war claims its wages from us,” he said.

But he also warned against a premature withdrawal from Iraq, which he said “would be an unconscionable act of betrayal, a stain on our character as a great nation.” In a jab at Democrats, Mr. McCain asked, “How can they argue at the same time for the morally reprehensible abandonment of our responsibilities in Iraq?”

In a response for Democrats, the chairman of the Democratic National Committee, Howard Dean, said, “John McCain’s empty rhetoric today can’t change the fact that he has steadfastly stood with President Bush from day one and is now talking about keeping our troops in Iraq for 100 years. His new appreciation for diplomacy has no credibility after he mimicked President Bush’s misleading case for a unilateral war of choice when it mattered most.”