The United States and Canada will temporarily suspend all non-essential travel between the two countries in the coming days as both try to slow the spread of coronavirus.

The closure is expected to be designed in such a way as to not slow cargo between the two countries. Detroit is the largest trading corridor between the two countries, which are two of the largest trading partners in the world.

Workers who live in either country but are employed in the other will be able to cross as well, though it was unclear how they would be screened. Few other details — including when it will go into effect — were not immediately known as more information was expected throughout the day Wednesday.

Brian Masse, a member of Canada's Parliament representing Windsor West, predicted the restrictions would take place very soon. "By tomorrow, it's going to be happening," he said.

President Donald Trump and Canadian Prime Minister Justin Trudeau announced the impending closure on Wednesday morning.

The Detroit-Windsor Tunnel remained open as of noon Wednesday but was preparing to close to non-essential travelers as required by the decision. Tunnel officials put out a statement saying, "Further clarification is expected in the near future on which workers (considered essential) are covered by this exemption and on the required documentation that will be needed."

Michigan includes two of the busiest border crossings with Canada, the Ambassador Bridge in Detroit and the Blue Water Bridge in Port Huron.

A source close to governments in both countries confirmed for the Free Press that not only will cargo continue to move but also workers. Some 6,000 people in the Windsor, Ontario, , region commute back and forth to Michigan to work, including some 3,000 health care workers.

Among them are 950 people who live in Canada but cross the border into the U.S. every day to work for Henry Ford Health System.

Patrick Irwin, Henry Ford's vice president of human resources, said Wednesday that he had been in communication with members of Congress, Vice President Mike Pence's office, and others to ensure its health care workers will be considered essential and will be allowed to cross the border.

However, he said negotiations are under way now to determine the details about how that will work. There's a chance Henry Ford's employees will be asked to all cross the border on one bus or on a shuttle rather than in their individual vehicles.

U.S. Rep. Elissa Slotkin, D-Holly, posted on Twitter that there are "lots of unanswered questions" Michiganders have about the impending closure. "I hope the administration will issue clearer communication very, very soon." she said.

"The northern border is a vital feature of Michigan's economy, and healthcare and other essential institutions depend on staff movement across the border," Slotkin said.

She added that that she and other members of Michigan's delegation had asked Pence this week to communicate with them any decisions made about the border.

That apparently didn't happen, she indicated.

Trump announced the impending closure on Twitter, saying, "We will be, by mutual consent, temporarily closing our Northern Border with Canada to non-essential traffic. Trade will not be affected. Details to follow!"

Trudeau had a televised announcement about various efforts in Canada to slow the spread of the virus, including the partial closure of the border on a temporary basis. He said, however, that it will "last as long as itneeds to last."

"In both of our countries, we recommend citizens stay home," Trudeau said. He said the closure affects travelers across the border interested in travel or recreation.

However, Trudeau said "essential trade will continue. Our governments recognize it is critical we maintain supply chains." Those supply chains include automobile parts and partial assemblies that move back and forth the border several times in the production of some vehicles.

Trudeau said he spoke to Trump by phone this morning.

The two countries were preparing to issue a joint statement in the next 24-48 hours, a Trump official told CNN.

Unites States and Canada have taken their own measures to slow down the spread of COVID-19, including Trump's travel ban from continental Europe, which was made "unilaterally and without consultation," EU Council President Charles Michel and European Commission President Ursula von der Leyen said.

However, the U.S./Canada travel restrictions will be a mutual agreement between the two countries.