Prime Minister Stephen Harper says it's likely British Columbia will need federal government financial disaster relief as vast parts of the province's forests go up in flames.

Harper was touring the Vancouver area on Tuesday as large swaths of the province burned and thousands of people were out of their homes, forced to evacuate because of 10 forest fires burning to close for comfort.

Harper told reporters he expects the costs of fighting the forest fires will trigger the federal government's Disaster Relief Act.

"Obviously, this is a very worrisome situation. We're watching this very closely," Harper said.

"We're always willing to provide whatever resources we can provide."

The prime minister said when damages reach a certain point, the Relief Act is triggered automatically.

"Do we expect it to be triggered in this case? I would think so," he said.

"But obviously the concern right now is less. . .about cost and just about making sure that this problem is effectively tackled."

British Columbia Premier Gordon Campbell joined Harper during the press conference on the Pitt River bridge. The bridge is slated to open by the end of the year and links Pitt Meadows and Port Coquitlam, just east of Vancouver.

Campbell said the federal government has been involved with the province as it deals with a forest fire season that's already seen more than 2,000 blazes. B.C.'s budget for forest firefighting for this year is $61 million, a figure that soon could be doubled.

"We don't ask for disaster financial assistance until we've got the disaster behind us. We think it's very important for us to deal with the people, the personnel, and the property first," Campbell said.

Thousands of people living near the Terrace Mountain fire in the Okanagan have had to flee, as well as thousands more in Lillooet because of the Mount McLean fire.

Harper is in B.C. for a two-day visit. He kicked off his trip by visiting the Olympic Oval that will host speedskating events during the 2010 Olympics.

He next stopped by the Pitt River Bridge as he and Campbell went for the inaugural walk across the recently completed concrete bridge deck.

The prime minister said the new bridge will improve the quality of life for families and workers in the area.

While taking questions from reporters, the prime minister was asked to weigh in on B.C.'s recent announcement that it will switch to a harmonized sales tax in mid-2010.

He responded by saying there's been a number of studies by credible organizations suggesting that harmonization of sales taxes has advantages for various provincial economies.

He noted that Atlantic Canada has had harmonized sales taxes for several years already.

"Our position has always been that other provinces are free to enter that harmonized arrangement on the same terms if they so choose. Ontario chose to do so, I think it was last year. And British Columbia's chosen to do so this year."

British Columbia is harmonizing its seven-per-cent provincial sales tax with the federal GST to create a single 12-per-cent tax starting on July 1, 2010.

The decision has been met with outrage by provincial Opposition New Democrats, as well as some consumers who will be paying more on everything from haircuts to carpet cleaning that today include only the five per cent GST.

Campbell defended the move.

"I think when people understand the importance of being competitive and creating an environment for investment they will understand the wisdom behind moving to an HST at this time," he said.

"Not only do we improve the competitive position of our construction industry, of our forest industry, of our mining industry, of our energy industry, we actually create an environment where people want to come and invest."

Campbell said switching to the HST will create jobs and allow B.C. to come out of the economic downturn even stronger.

"We know that this is going to be difficult for some sectors of the economy. We want to work with those sectors to make sure it works," he said.

Harper is expected to visit Victoria Wednesday morning, before leaving B.C. in the evening.