Barack Obama is set for a major overseas trip that will include stops in Europe, the Middle East and perhaps Iraq.

The trip marks his first high-profile step onto the international stage, a campaign-season audition of sorts for a presidential hopeful pledging a new era in diplomacy and an end to the U.S. combat role in Iraq.

His precise itinerary is being kept secret for security reasons. It is known that he will meet next Wednesday with Palestinian President Mahmoud Abbas in Ramallah, a Palestinian Authority spokesman confirmed. And German officials expect to welcome him on Thursday.

"The stakes are very high for Obama," said Lee Hamilton, president of the Woodrow Wilson International Center for Scholars and a supporter of the Illinois Democrat.

While Obama currently leads in the polls, "foreign policy is one area where they (voters) have their doubts" about him, Hamilton said.

The trip is planned to put Obama into settings often occupied by presidents, including formal meetings with foreign leaders, public speeches and visits to historical sites.

"It's an opportunity for him to sit down with the international leaders with whom he would have to work as president of the United States, and discuss some of the issues," said David Axelrod, the campaign's senior strategist.

Obama has been critical of President George W. Bush's foreign policy in his campaign for the White House -- and has sought to tie it closely with his Republican rival, John McCain -- but Hamilton said the Democratic presidential nominee-in-waiting must tread lightly. "Criticizing foreign policy in Washington in one thing. Criticizing it in Berlin" is another, he said.

"There will be a lot of eyes on him, and we know that," Axelrod said, when asked about the risk of politically damaging errors.

To further magnify the scrutiny, all three network news anchors are expected to tag along for the trip, each of them seeking one-on-one interviews.

The media glare is to be expected, Paul Friedman, senior vice president for news at CBS told National Public Radio.

"This is a new candidate. Many people have more questions about him than about his opponent," he told NPR. "He's clearly been challenged on the issue of what he knows about foreign policy and national security policy. He's making this trip in response, to a large degree, to this kind of criticism. It's our job to go cover him."

McCain Says It's About Time

McCain's spokeswoman, Jill Hazelbaker, said the trip is about politics and an effort to "compete" with McCain on foreign policy credentials.

McCain has visited Iraq eight times, Obama just once, and the Republican Party on its Web site is counting the number of days until Obama visits again. It was 921 days as of Thursday.

Asked later whether he thought Obama's trip to Iraq and Afghanistan was a political stunt, McCain said he did not.

"The fact is I'm glad that he's going to Iraq. I'm glad that he's going to Afghanistan. It's long, long overdue if you want to lead this nation and secure our national security," he told reporters on his campaign bus.

"If he was so concerned about Afghanistan and the threat there and the need to send additional troops, don't you think he should have gone there?" McCain asked.

Later in the day, however, he said he thought other parts of the trip seemed geared toward politics, not the visits to the war zones.

Taxpayers Footing Candidates' Trips

McCain visited Iraq in March, also during the campaign year, and taxpayers financed that trip. They will do the same for Obama.

That's because, as a member of the Senate Foreign Relations Committee, Obama is allowed to travel the world at government expense to learn firsthand about foreign-policy issues before Congress.

McCain's visit to Iraq in March was an official trip of the Armed Services Committee. Members of that panel frequently travel abroad to meet with troops and their commanders.

Before leaving the United States, McCain, one of the foremost proponents of the March 2003 U.S.-led invasion, said the trip to the Middle East and Europe was for fact-finding purposes, not a campaign photo opportunity.

When Obama's travel was announced, he said the travel would be "an important opportunity for me to assess the situation in countries that are critical to American national security, and to consult with some of our closest friends and allies about the common challenges we face."