Canada said Thursday it has approved design changes that Boeing made to 737 MAX planes after two fatal crashes led to the aircraft being grounded for more than a year.

But Canada added the plane was not yet cleared to fly again in its airspace, even though the jet has been certified to do so by regulators in the US.

The Canadian transport ministry said this validation of the design changes after the crashes that killed 346 people in 2018 and 2019 "is an important first step in the eventual return to service of this aircraft in Canadian airspace.

-However, the return to service is complex, and Transport Canada must put in place comprehensive safety plans that require additional aircraft changes, maintenance and training- it said.

The ministry said that in January it will issue an airworthiness directive spelling out design changes that must be incorporated in 737 MAX planes registered in Canada.

It will also mandate training requirements for crews operating these planes.

Last week the Brazilian airline Gol became the first in the world to put the 737 MAX back into service.