Canadian Prime Minister Stephen Harper will start what his country's media says is his "most important foreign visit" when he arrives in China today.

Harper is hoping to reenergize stagnated ties with Beijing and inject vitality into the Canadian economy.

Chinese experts said that, despite the shadow cast by Ottawa's high duty on Chinese steel imports, the visit is likely to show Canadian goodwill and could be a turning point in the relationship between the countries.

It is Harper's first visit to China since he took office in 2006.

Ottawa has aggressively criticized Beijing for its human rights record and for alleged spying. Harper was not among world leaders at the 2008 Olympics in Beijing, and he irritated China by embracing the Dalai Lama.

However, an aide to the prime minister signaled a shift in Ottawa's China policy ahead of the visit, telling media "new global realities demand a modernized Canada-China relationship".

"The prime minister's visit will be a key opportunity to extend our presence in China and to promote Canadian interests," Dimitri Soudas, said on Sunday.

In another positive sign, the spokesman avoided responding to a question about whether Harper will ask for the value of the yuan to be allowed to rise, a request that Premier Wen Jiabao rebuffed during Monday's summit with European leaders.

"Just like he doesn't comment on the value of the Canadian dollar, he doesn't comment on the value of other currencies," Soudas said.

Chinese experts have said the apparent change in Ottawa's attitude was driven by criticism from Canadian businesspeople seeking opportunities in China in the face of losses brought about by the sluggish US economy.

Pang Zhongying, an international affairs expert at Renmin University of China, said that following the financial crisis and US President Barack Obama's four-day visit to China, Canada had "second thoughts about its attitude toward China".

The visit comes after China-Canada trade reached a historic high of $50.3 billion last year. China is now Canada's second-largest merchandise trading partner and is expected to become Canada's second-largest merchandise export market this year.

"China's huge domestic market and its role as one of the world's largest exporting nations will be an essential element of the global recovery," Soudas said.

China's Foreign Ministry spokesman Qin Gang told reporters "China attaches great importance to the visit" and expects it to promote relations.

Canada has carefully paved the road for Harper's visit by sending four ministerial visits.

Harper will take his agriculture and trade ministers to meetings with President Hu Jintao and other leaders.

But Zhu Feng, an international relations professor with Peking University, cautioned that the visit is happening at a bad time, with a new preliminary duty of up to 182 percent on Chinese steel imports casting a shadow.

"The duty will be temporarily good for the Canadian economy but it will definitely impact the warming relations," Zhu said. "I think Canada should turn to other channels, such as the World Trade Organization, for a better result."

The Canadian Press, Canada's national news agency, pointed out that "reaction to a similar move by the US (after it imposed duties on Chinese goods) indicates Canadian-Chinese trade relations could suffer as a result".

Soudas has downplayed the possibility of major agreements during the trip.

"We will not transform the bilateral relationship overnight," he said.

Former Canadian trade minister David Emerson, however, told Canadian Press on Sunday that success for Harper should not be judged by whether he comes away with deals. Emerson said it will be measured by whether he can secure hard commitments on a "process to pursue fundamental arrangements we need for concrete progress over a long period".