The U.S. and Canada look set to extend a ban on non-essential travel until June 21 amid the COVID-19 pandemic, Reuters reports quoting unnamed sources from both sides.

The two countries extended border restrictions on April 21 as both recorded rises in their infection and fatality numbers.

"It's too early to lift the restrictions, so we're working toward an extension," said one Canadian government source, describing the talks with Washington as positive. A second government source said the discussions had been collaborative.

In Washington, a U.S. official confirmed the two sides were set to agree on a 30-day extension.

The U.S. is the worst affected country globally by the COVID-19 pandemic, having registered close to 4.3 million cases and 82,548 fatalities, according to the U.S.-based Johns Hopkins University.

Canada on the other hand has reported more than 72,000 infections and 5,300 deaths.

Prime Minister Justin Trudeau said on Tuesday Canada was "looking at stronger measures" to ensure COVID-19 was not being spread by border crossers, but gave no details.

News of the Canadian request for a 30-day extension was first reported by the Globe and Mail newspaper.

The agreement allows the flow of goods across a border that stretches 8,891 km (5,525 miles) and is a crossing point for one of the world’s largest bilateral trading relationships.

Canadian officials have been repeatedly pressed about the potential risk posed by arriving truck drivers.

Theresa Tam, Canada's chief public health officer, on Tuesday said the coronavirus "could take off rapidly" unless extreme caution was exercised about relaxing the ban.