The Toronto Zoo is hoping two giant pandas that will take up residence there for five years can save the city-owned facility from extinction.

Prime Minister Stephen Harper wrapped up a visit to China by officially announcing Saturday that Beijing will loan two pandas to Canada.

Er Shun and Ji Li will spend five years in Toronto before heading to Calgary for five years.

The giant panda is unique to China and is regularly sent abroad as a sign of warm diplomatic relations or to mark breakthroughs in ties. The Toronto Zoo just hopes it will mean a breakthrough in attendance.

"This is going to be unprecedented for the zoo," said Coun. Giorgio Mammoliti.

Mammoliti said he's always been frightened a decline in attendance numbers at the zoo would eventually mean its closure, but he hopes the pandas will attract 2.5 to 3 million people annually.

A giant panda stayed at the Toronto Zoo in 1985, attracting 750,000 visitors in just three months.

"The zoo will break even on this panda exhibit and then some," said zoo chair Joe Torzsok. "And that money will be used to support our conservation, education and research work. We're absolutely certain this is no cost to the taxpayers."

Taking in the pandas is costly. An $800,000 pen upgrade was already planned and will now cost more, the rent on the pandas is $1 million a year and there's an extra $200,000 charge if a cub is born. That's all on top of food, which can cost close to $200,000 a year.

"In the past zoos have not made that much money from pandas, so the outlay on the zoo's part is quiet enormous," said Henry Nicholls, author of The Way of the Panda. "What happens quite quickly is you do get an initial increase in visitor numbers but that tails off rather rapidly."

To combat that, the pandas will make the move to Calgary.

The animals arrive in the spring of 2013.