Canada says it wasn't given enough warning and has asked Russia for more information about a rocket stage that is expected to splash down this weekend in environmentally sensitive Arctic waters.

"The Government of Canada has sought clarification from the Government of Russia regarding the lack of sufficient notification of this rocket launch," Austin Jean, a spokesman for Global Affairs Canada, said in an email Wednesday.

"We have stressed to the Government of Russia the need for greater advance warning of planned launches to ensure that all precautions, relating both to the safety and security of our airspace and any potential environmental concerns, can be appropriately addressed."

The Russian Embassy in Ottawa said the federal government was made aware of the launch.

"With regard to the inquired rocket launch, the Canadian side was informed it would be done in a way that no territory of Canada or its territorial waters would be affected while the fuel of disposed rocket stages fully burn out," Kirill Kalinin, press secretary for the Embassy of the Russian Federation in Canada wrote in an email.

"In this context environmental concerns are seriously taken into account."

Late last week, an international civil aviation authority issued a warning that a stage of a Russian satellite-launching rocket would be falling into Baffin Bay between Ellesmere Island and Greenland.

The impact is expected to happen outside Canadian territorial waters, but within seas over which Canada has economic control.

The area is heavily used by Inuit from Canada and Greenland. It is also within the North Water Polynya, a large area of ocean that stays relatively ice free all year. It's a known hot spot for a wide variety of mammals, including whales and polar bears, as well as millions of seabirds and shoals of cod.

It is considered the most biologically productive ecosystem north of the Arctic Circle.

The Russian rocket, a Cold-War-era ballistic missile repurposed for civilian use, is known to be fuelled by hydrazine. Hydrazine is highly toxic and Russia is one of two countries in the world that continue to use it as a launch propellant.

Austin said the fuel in Saturday's rocket is expected to burn completely during re-entry.

"We therefore expect minimal environmental risks."

Still, he said, Canada doesn't look favourably on such space debris landing on its land or water.

"We have also urged in certain terms that the Russian government make every effort to ensure that debris does not land on Canadian soil or within our exclusive economic zone.

"This issue is governed by a number of international treaties. Canada expects Russia to fully comply with its obligations in this regard."

The North Water Polynya -- the largest in the Arctic at 85,000 square kilometres -- is highly valued by Inuit in Canada and abroad. The Inuit Circumpolar Council has established a commission to ensure it is managed sustainably as northern waters gradually open up.