Prime Minister Stephen Harper has landed in London to meet with G20 leaders for discussions on how to restore the struggling global economy.

U.S. President Barack Obama, and other leaders, also arrived Tuesday night for the emergency summit meeting in search of an economic silver bullet.

There some significant disagreement between G20 leaders on what is the solution for the flailing global economy. The U.S. and the U.K. want more stimulus spending, while mainland Europe prefers more regulation for the financial sector.

CTV's London Bureau Chief Tom Kennedy told Power Play "the President of France (Nicolas Sarkozy) has implied that he will walk out of this summit if there is too much talk about economic stimulus and not enough talk about the root of what he describes as the real problem, (Anglo-American) bankers."

The meetings will be Obama's first major test on the global stage as president. But he can expect to find resistance on his economic strategy.

"There are significant differences on that key issue (of stimulus,)" Kennedy said, also citing the German chancellor and Czech prime minister as politicians who are opposed to more stimulus spending.

World leaders will also discuss giving more cash to the IMF and the World Bank to help developing countries make it through the global recession.

However, the Canadian government says such aid is "secondary."

"No amount of foreign aid and assistance will be sufficient," Harper's spokesman, Kory Teneycke, said at a pre-summit media briefing.

Kennedy said an agreement already seems in place for the G20 to stamp out international tax havens, which wealthy citizens can use to hide income from their government.

Obama, Harper speak

Prior to his departure, Harper spoke with Obama about their shared priorities going into the summit.

The two leaders also spoke about the auto sector and the upcoming NATO summit, which kicks off in France on Friday.

At the G20 meeting, which begins Wednesday, Harper is expected to tout Canada's prudent economic policy.

In an interview with CNN Monday, Harper said Canada was criticized a few years ago for not deregulating banks but he said that has now helped make Canadian banks among the strongest in the world.

Teneycke said the best solution is to restore global economic growth through better financial regulation, freer trade and dealing with toxic assets.

The G20, which includes China, Russia and India, comprises 90 per cent of world trade.

It also boasts more than 80 per cent of economic output and two thirds of the global population.

Major protest expected

Kennedy said that protesters are expected and Wednesday has been designated "Financial Fool's Day" by activists in London.

The security for the conference is being referred to as the most sophisticated to ever take place in London.

"They are not sparing any hyperbole to describe about what is going to happening here over the next few days," Kennedy said. "They are calling it the 'summit to save the world,' so the security around it is enormous."

On Friday, both Harper and Obama will be attending the NATO summit in Strasbourg, France.

The focus there will be on the mission in Afghanistan.

During his trip, Obama is also expected to visit with the Queen at Buckingham Palace and make a trip to Turkey.

With files from The Canadian Press