The Federal Minister of Transport is adamant there will be only two bridges over the Detroit River.

Marc Garneau says the old Ambassador Bridge will be demolished once the new crossing is ready for use.

“That is something that the Canadian Transit Corporation has to deal with it as a pre-condition to building a replacement bridge.”

Garneau, a former astronaut, met with Windsor Mayor Drew Dilkens on Friday to shed some light around what will happen with the 87-year-old span.

Garneau says he wanted to take the opportunity to let Dilkens know that the permit to build a new bridge comes with a clear condition that the old bridge will be demolished, and it will be unacceptable to remain in place.

But according to the Detroit International Bridge Company, the U-S permit calls for the old bridge to be saved for its historical significance.

Garneau adds the new bridge will only be built once all of the conditions of the permit are met. That includes an environmental evaluation and cost associated with tearing down the current structure.

If the corporation is not able to provide the government with all the information, Garneau says the new bridge will not be authorized.

Some people have suggested both countries should keep the old Ambassador Bridge and make it a pedestrian friendly walkway. But Garneau says he doesn't think it will be safe enough for any type of transportation.

The Detroit International Bridge Company received the permit for the new bridge from the Canadian government in September. The company says the new $1-billion crossing will be built by 2020.

Garneau, a former astronaut, also insists Gordie Howe International Bridge will be built "100 per cent" and work will begin before the end of 2018.

“I'm not going to give you a date at this point” says Garneau. “We need to see the final bids and final proposals and what their timelines are and what the costs are before we choose a winning bid and that will give us a better idea of when it will be completed.”

Garneau is in Windsor to attend the Governors and Premiers of the Great Lakes and St. Lawrence River meeting this weekend.