The presumptive Republican presidential nominee, Senator John McCain, spoke about the dangers of nuclear proliferation Tuesday in a speech in Denver, Colorado.  Meanwhile, there is only one week left in the Democratic primary battle between Senators Barack Obama and Hillary Clinton.  VOA National correspondent Jim Malone reports from Washington.

Senator McCain said as president he would ensure U.S. leadership to stem the spread of nuclear weapons.  McCain said his approach would not rely too heavily on either direct talks with adversaries or the threat of military force.

"Our highest priority must be to reduce the danger that nuclear weapons will ever be used," he said.  "Such weapons, while still important to deter an attack with weapons of mass destruction against us and our allies, represent the most abhorrent and indiscriminate form of warfare known to man."

McCain's speech was interrupted several times by anti-Iraq war protestors, prompting McCain to restate his pledge to remain in Iraq until the U.S. achieves victory there.

"And by the way, I will never surrender in Iraq, my friends, I will never surrender in Iraq," he added.

McCain hopes to benefit this week from fundraising help from President Bush.  Tuesday's fundraiser in Arizona marks their first joint appearance since the president endorsed McCain at the White House nearly three months ago.

Meanwhile, the Democratic primary race between Senators Barack Obama and Hillary Clinton is now in its final week.

Clinton has been campaigning in the U.S. Commonwealth of Puerto Rico, where she is favored in Sunday's primary.

"I pledge to you that I will end the war in Iraq, bring our troops home and take care of our veterans the way they should be cared for!" she said.

Senator Obama is favored in the last two primaries on June 3, in Montana and South Dakota.

Increasingly, Obama has been ignoring Senator Clinton and focusing instead on Senator McCain.

"He deserves admiration for his service to our country, but he is running for a third Bush term," he said.  "Look at his foreign policy.  He wants to continue a war without end."

Obama is expected to hold a significant lead over Clinton in the delegate count when the primaries end on June 3.  Most experts predict that the Democratic race is likely to end soon thereafter.

John Fortier monitors U.S. politics at the American Enterprise Institute and was a guest on VOA's Encounter program.

"Ultimately, Hillary Clinton is running out of time," he explained.  "There is not much left for her.  They are both doing well, and Hillary Clinton may end up with a few more delegates in the last few contests, but she is not going to catch him.  And we are likely to see, I think, June as the time where ultimately she sees that the handwriting is on the wall, the vote is official, and she probably concedes in a week or so after the last primary."

The Democrats hold their national nominating convention in Denver in late August, while the Republicans meet in Minneapolis-St. Paul the first week in September.