Ontario Premier Doug Ford enlisted a giant chart comparing the province's low COVID-19 caseload per capita with staggering U.S. case counts as he continued to urge the feds to keep the border closed and chided U.S. President Donald Trump for his trade protectionism.

"You can see we are at 284 cases per 100,000 people," Ford said proudly, pulling the chart onto a stand in the middle of his afternoon press conference.

Next to Ontario on the chart was Quebec, at 726 cases per 100,000, and then Michigan at 989, Pennsylvania at 994, all the way to Florida with 2,827 cases per 100,000.

"I love our American friends but this is the reason prime minister, we can't open the borders, it's very simple," Ford said.

The federal government and American authorities have agreed to keep land borders closed to non-essential travel until Sept. 21.

Air travellers from the U.S. can arrive but must self-isolate for 14 days upon arrival.

The chart, which counts lab-confirmed tests per 100,000 people, does not include any other Canadian province except Quebec.

That means it leaves out provinces who per capita have demonstrated far lower rates of infection.

British Columbia, albeit slightly more than one third Ontario's size, has seen only 105 lab-confirmed COVID-19 cases per 100,000 people since the pandemic reached Canada in January, less than half of Ontario's rate.

Also, blood antigen surveillance data collected by Public Health Ontario in the spring suggested Ontario's initially low testing rates mean more than three of every four COVID-19 infections was missed by the end of June.

Ford said he wanted to compare Ontario to U.S. jurisdictions due to similarities in their size compared to Ontario.

"Next to California, Texas, New York and Florida we'd be the fifth largest population (if Ontario were a U.S. state). I just wanted to show the people they're doing a good job. We're not out of the woods by any means but I just want to encourage people," he said.

He conceded that America, with the largest burden of novel coronavirus cases and deaths in the world, is a different country with a different experience in the pandemic than Canada.

"We're different than the U.S. – Canadians listen a lot more than Americans do and I appreciate it."

When asked about whether he would indicate a preference in the U.S. presidential race, he first said he is "so focused" on dealing with provincial matters, but then let his frustration about Trump's latest tariffs on Canadian exports get the better of him.

"Trump's up there saying 'I am going to tariff this, tariff that,' and you know he should do a little homework. Find out that we're their number one customer. We buy more off the Americans than China, UK, Japan combined. We are their number one customer and he wants to come after us over politics? Let him."

He said Finance Minister Chrystia Freeland recently asked him to call U.S. Trade Representative Robert Lighthizer regarding the new tariffs on Canadian aluminum exports.

"Don’t even get me going on this; I get too worked up when someone comes after our country or our province."