WASHINGTON — The US government on Tuesday extended for another month restrictions on non-essential travel across the borders with Canada and Mexico to help stop the spread of the novel coronavirus.

The US Department of Homeland Security said the closure, first ordered on March 20 and due to expire Wednesday, will be extended until June 22 and reviewed every 30 days.

"Non-essential travel will not be permitted until this administration is convinced that doing so is safe and secure," said interim DHS chief Chad Wolf.

"We have been in contact with our Canadian and Mexican counterparts and they also agree that extending these restrictions is prudent at this time. We appreciate our partnership with Mexico and Canada in ensuring that North America is working together to combat the ongoing global pandemic," he said.

In Ottawa, Prime Minister Justin Trudeau announced earlier that the Canada-US border will remain closed to all non-essential travel for another month, until June 21 to fight the spread of the coronavirus.

The world's longest international frontier at 8,900 kilometres was closed to travellers on March 21, but trade in goods has continued.

The prime minister also left open the possibility of further extensions.

"We will continue to watch carefully what's happening elsewhere in the world and around us as we make decisions on next steps," he said.

Mexico shares a 3,100 kilometre (1,900 mile) border, and travel limitations have been in place since March 20. As in the Canadian case, trade in goods continues.

The United States, Canada and Mexico have been part of a regional free trade agreement since 1994. — AFP