Thousands of U2 fans booed beleaguered Prime Minister Paul Martin at a sold-out concert in Vancouver. Prompted by U2 front man Bono, they were reminded Martin broke a promise by not raising Canada's spending on foreign aid.

But that doesn't mean Martin is off the hook. Bono, a long-time activist for Third World debt relief, says he's not giving up on Martin. He asked the crowds not to give up on him either.

"I think we're going to figure this thing out. I think he's a great leader for Canada and that he can do what we want him to do, to lead the world out of despair and poverty, this year."

Bono went on to challenge Martin, asking him to deliver on the commitment to raise Canada's foreign aid spending to 0.7 per cent of the country's GDP by 2015. He even went on to flash a phone number on screens above the stage, asking fans to call the Prime Minister's Office to remind Martin of his promise.

"If you people believe in it, I believe Paul Martin is the kind of person who will listen to you," Bono said. "Get out your phones. Dangerous little devices, these cell phones."

As the glow of dialing cell phones lit Vancouver's GM Place, Bono stayed on message. "We want to make poverty history," he screamed. "This is the year!"

The calls were still coming in Friday.

"I know I called this morning and the woman sounded very distressed," concert-goer Michelle Maltais told CTV News. "She's like, 'oh yeah, we've had a lot of calls about that.'"

Martin, meanwhile, insists that he's not offended by the antics of his rockstar pal.

"He's been very supportive and he's a friend, but he's doing what he ought to do," said the Prime Minister in Regina on Friday.

"He's essentially saying, come on, we want to push you to the 0.7. My position on the 0.7 is very clear: I support Canada going to 0.7. And I support it very strongly."

But Martin wasn't willing to guarantee that he'll get to that level by 2015.

"I'm not prepared to make a commitment that I cannot guarantee we will attain," he said.

U2 fan Kieran Kennedy, who watched the concert Thursday night from the floor, agreed Martin should follow through on his promises. "Paul Martin should give more money to the Third World, not because Bono says so, but because he himself promised to."

Many fans also showed their support for more foreign aid by wearing white rubber bracelets in support of the cause. Printed on them is the message 'Make Poverty History.'

The bracelets were handed out in exchange for a donation to a campaign being backed by Bono and other celebrities, including Sarah McLachlan, Brad Pitt, Cameron Diaz and Jamie Foxx.

The campaign will officially kick off in Canada Friday, when a downtown Vancouver church will be wrapped in a white band.

Bono also took the chance to praise Vancouver. "I first came here in a building that's knocked down now," he said. "Just watched the city grow and grow. From the first, I always liked walking the streets of Vancouver."

With reports from CTV News and The Canadian Press.