The Canadian dollar has the nickname "loonie"

Traditionally the poor neighbour, one Canadian dollar is now worth 90 US cents. Some analysts say it may soon be on par with its American namesake.

The US dollar has weakened against most main currencies in recent weeks, while the Canadian dollar has gained on optimism about Canada's economy.

The Canadian dollar gets its nickname from a loon bird depicted on the coin.

Washington has seen the dollar weaken due to a number of factors, including concern over America's ongoing trade deficit, and recent suggestions by US Federal Reserve chief Ben Bernanke that the current cycle of US interest rate rises may be coming to an end.

While the strength of the Canadian dollar is good news for Canadians travelling to the US, and Canadian firms importing from the US, it makes things more difficult for Canadian companies exporting south of the border.

The Canadian dollar has not traded above 90 cents since February 1978, but closed just below that mark in November 1991.