Speaking at a campaign rally in Denver, McCain said while the United States and Russia still have "significant differences," the end of the Cold War means that the two countries are no longer "mortal enemies."
"As our two countries possess the overwhelming majority of the world's nuclear weapons, we have a special responsibility -- the two of us -- to reduce their number," McCain said, in what was billed as a major foreign-policy speech. "I believe we should reduce our nuclear forces to the lowest level we judge necessary, and we should be prepared to enter into a new arms-control agreement with Russia reflecting the nuclear reductions that I'll seek."
McCain's proposal represents a clear departure from the policies of the administration of President George W. Bush, which has never accepted the idea of limits on nuclear weapons.
"The Cold War ended almost 20 years ago," McCain said, "and the time has come to take further measures to reduce dramatically the number of nuclear weapons in the world's arsenals."
'Enhance Confidence, Transparency'
McCain said the United States should strike a deal with Russia that would replace verification requirements in the Strategic Arms Reduction Treaty, known as START, which expires in 2009.
"We should be able to agree with Russia on binding verification measures based on those currently in effect under the START agreement, to enhance confidence and transparency," he said, adding that Russia and the United States should find ways to "reduce and hopefully eliminate" tactical nuclear weapons in Europe -- a policy also opposed by the Bush administration.
McCain spoke of working with Russia to build confidence in the idea of a missile-defense shield, which he said could include sharing data on early warnings and giving prior notification of missile launches. Russia opposes U.S. plans to establish a missile-warning and defense system in the Czech Republic and Poland.
McCain's speech was interrupted four times by antiwar protesters, who chanted, "End this war!"
"I will never surrender in Iraq, my friends," McCain responded. "I will never surrender in Iraq."
Threats From Iran, North Korea
McCain also spoke of North Korea and Iran. He said the elimination and verification of North Korea's nuclear program should be one of the highest foreign-policy priorities of the United States.
Iran, he said, poses an equally grave threat.
"We've seen Iran marching, marching with single-minded determination toward the same goal [of obtaining nuclear weapons], authenticated again today by the IAEA," McCain said. "President [Mahmud] Ahmadinejad has threatened to wipe Israel off the face of the Earth and represents a threat to every country in the region -- one we cannot ignore or minimize."
Both of the Democratic candidates in the presidential race -- Senators Hillary Clinton and Barack Obama -- also have called for a world free of nuclear weapons.
The Obama campaign issued a statement saying McCain had "embraced many aspects of Barack Obama's nonproliferation agenda."