Two giant pandas arriving from China in 2013 are expected to draw an additional 500,000 visitors to the Toronto Zoo in their first two years here, zoo officials say.

The five-year-old pandas, a male named Er Shun and a female named Ji Li, will be at the Toronto Zoo for five years before heading to Calgary.

Prime Minister Stephen Harper clinched the so-called "panda diplomacy" deal with Chinese officials during his trade trip to China this week.

It will cost about $1 million a year to host the pandas, but zoo officials say the anticipated jump in attendance will help them recoup the cost.

The Toronto Zoo experienced its highest annual attendance ever – 1.9 million visitors – in 1985, when it housed pandas for only three months. The zoo typically draws an average of 1.3 million visitors a year.

This time, the zoo is also counting on the influx of athletes and tourists during the 2015 Pan Am Games in Toronto.

Joe Torzsok, chair of the Toronto Zoo Board, said staff are excited to welcome the pandas in 2013 after more than a decade of planning.

"This acquisition reflects the dedication of several zoo staff, board members and friends of the zoo over the past twelve years who shared the vision of a giant panda conservation program," he said in a news release.

The pandas are expected to draw large crowds not just from the GTA, but other parts of North America as well, Torzsok told CTV Toronto.

The panda conservation is part of the zoo's 25-year master redevelopment plan. Construction of the pandas' new sanctuary is expected to begin in the next few months.

If Er Shun and Ji Li breed in Toronto, they will remain at the zoo along with their offspring until they're deemed ready for another move.

"We are honoured to host the pandas at the Toronto Zoo and contribute to the survival of the species for generations to come," said John Tracogna, Toronto Zoo CEO.