U.S. President Donald Trump said on Twitter that the U.S. will temporarily close its northern border with Canada to non-essential traffic due to the novel coronavirus, adding that trade won't be affected.

Canadian Prime Minister Justin Trudeau said Monday he would close the country's borders to anyone not a citizen, an American or a permanent resident, and even then they must self-isolate for 14 days on arrival.

Trudeau said the exemption for Americans, despite the rapid rise of cases in the U.S., was due to "the level of integration of our two economies."

The United States has seen about 6,500 coronavirus cases and more than 110 deaths while Canada has seen about 600 cases and eight deaths.

Canadian Deputy Prime Minister Chrystia Freeland said the border is vital to the daily life of people on both sides. 

"Nearly 200,000 people cross that border every day, and that border and that traffic that goes across that border is literally a lifeline for both the Canadians and the Americans on both sides of that border," Freeland said.