Prime Minister Stephen Harper says there are better ways for Washington to raise money than to charge Canadians who travel to the United States.

U.S. President Barack Obama is proposing a $5.50 "passenger inspection fee" for Canadians. The proposal is contained in the 2012 draft budget he submitted to Congress on Monday.

Until now, visitors from Canada -- as well as from Mexico and selected Caribbean countries -- have enjoyed a waiver from the fee. But Obama's budget blueprint notes that charging the fee to Canadians would add millions to U.S. government coffers and would help offset the costs of increasingly intensive air-passenger inspections.

Harper told reporters Thursday that while the U.S. is facing "enormously challenging" financial problems, he believes that collecting fees from Canadians is not a "useful" way of raising money.

"We want to ensure that trade and travel is easier, not more difficult, and we don't need additional taxes on that kind of economic activity," said Harper.

The proposed charge to Canadian travellers would apply only to those arriving by air or ship, not private vehicles. That's likely to please the growing number of Canadian vacationers who drive across the border before flying to their holiday destinations.

According to Statistics Canada, some 16 million Canadians flew into the U.S. in 2009. The $5.50 head tax would add almost US$90 million to U.S. government coffers.

Michael MacKenzie of the Canadian Snowbird Association says the proposed fee would be annoying for Canadians, but he doesn't think that it will stop them from going to the U.S.

The U.S. is by far the most visited destination for Canadian tourists, who took 4.1 million trips to its southern neighbour in December, according to statistics reported on Thursday.

In all, Canadian residents took 4.8 million trips abroad in the last month of 2010, up 2.3 per cent from the previous month.

Same-day car travel to the U.S. rose 6.7 per cent to 2.3 million trips in December, the highest level in three years, while air travel in December rose 1.1. per cent to 592,000 trips.

Travel from the U.S. to Canada, however, declined 1.6 per cent to 1.7 million trips in December.

The proposed fee comes just a week after Harper and Obama agreed to a deal that would establish a North American security and trade perimeter.

In Ottawa, Liberal Leader Michael Ignatieff said the proposed fee appeared to be a "nasty surprise" dropped on the Canadian government from Washington.

The issue was also brought up in the House of Commons during question period, when Liberal industry critic Marc Garneau suggested that the Conservative government was not able to protect Canadian interests and that the proposed fee was indicative of deteriorating ties between the two countries.

In response, Foreign Affairs Minister Lawrence Cannon said the fee is only at a proposal stage and that the two governments have been working to increase prosperity for both countries.

Asked further about the issue by NDP industry critic Brian Masse, Cannon said that it was the government's position that the proposed fee was a "bad idea."

Birgit Matthiesen, the Washington-based envoy for the Canadian Manufacturers and Exporters organization, said it appeared the U.S. president's proposal could be part of an unpopular trend.

"It's revenue collection, and the mindset seems to be rather than taxing your own citizens, let's go tax someone else," Matthiesen said Thursday.

Chris Sands, a senior fellow at the Washington-based Hudson Institute, said the U.S. Department of Homeland Security has taken on increased security costs in recent years and the government may see the proposed fee as a justifiable measure.

"I don't think it's meant particularly in a mean way towards Canadians, but DHS is under budget pressure like everybody else and revenue is hard to come by in this town, so I think that's where this is coming from," Sands told CTV's Power Play from Washington on Thursday.

With files from The Canadian Press