Canadian Prime Minister Justin Trudeau said Wednesday that the United States and Canada had agreed to close their 5,500-mile border to "all nonessential travel" as the deadly coronavirus outbreak continues to spread.

Trudeau spoke after President Donald Trump tweeted the plan to close earlier Wednesday. The world's longest undefended border was being closed with the "mutual consent" of Canada, Trump said, and would not impact trade.

Trudeau agreed the decision was mutual. He vowed to "ensure the smooth flow of goods and essential materials and medication." He described new spending to ease the impacts of the coronavirus outbreak on Canadians.

Trudeau spoke outside Rideau Cottage, an official residence in Ottawa, where he has been working in self-isolation since his wife, Sophie Grégoire Trudeau, tested positive for covid-19 last week.

Trudeau said the border restrictions "will last in place as long as we feel that they need to last. We will again closely coordinate on that as well."

The Canadian Broadcasting Corp. said a start date would be announced soon.

Canada has confirmed around 600 cases of the coronavirus, according to a count kept by the Johns Hopkins University. At least eight people have died. The United States has confirmed more than 6,400 cases, with patients now in all 50 states and the District of Columbia. More than 110 people have died.

Trudeau announced the closure of Canada's borders to most travelers on Monday, but exempted U.S. citizens, Canadian citizens and permanent residents. Nearly 200,000 people cross the border each day, Deputy Prime Minister Chrystia Freeland said Tuesday.

U.S. residents spent more than $6 billion in Canada in the first three quarters of 2019. In December, more than 2.3 million vehicles entered Canada from the United States. More than 1.6 million were Canadian vehicles returning to the country. U.S. trade in goods with Canada exceeded $600 billion in 2019.

The move was similar to a decision made by the European Union this week, which temporarily banned most foreign travelers.

Trudeau had indicated that a closure of the Canadian border with the U.S. could be an option.

Trudeau told the Canadian Broadcasting Corp. last week that Canadian officials were "in the midst of co-ordinating with the Americans, obviously, on our borders, on our actions. We'll continue to evaluate what we can do and how we can keep Canadians in security and we won't close the door on any idea."