U.S. extends border restrictions on Canadians. Trudeau asked about re-sealing frontier to Americans.

OTTAWA, Ont. — The U.S. is extending its border restrictions on Canadians for at least another month. And now Justin Trudeau is being asked if he might re-shutter Canada's frontier to Americans.

A Delta-driven surge in Covid-19 on both sides of the boundary is challenging each country's approach to the flow of travelers.

The U.S. decision: Despite political and business-led pressure, the Biden administration has appeared to be in no hurry to ease measures at U.S. land crossings, which are shut to discretionary travel.

The U.S. will keep restrictions in place until at least Sept. 21 in a move announced Friday by the Department of Homeland Security.

"To minimize the spread of #COVID19, including the Delta variant, the United States is extending restrictions on non-essential travel at our land and ferry crossings with Canada and Mexico through September 21, while continuing to ensure the flow of essential trade and travel," DHS wrote on Twitter. "In coordination with public health and medical experts, DHS continues working closely with its partners across the United States and internationally to determine how to safely and sustainably resume normal travel."

The Biden administration had been expected to extend the public health restrictions, which were put in place in March 2020 to limit Covid's spread.

Status check on Canada: In contrast, Canada started welcoming fully vaccinated U.S. visitors Aug. 9. The country has higher vaccination rates than the U.S., though it is dealing with a fourth wave of the pandemic.

Trudeau, who is campaigning for re-election as prime minister, was asked by a reporter Friday what it would take to make him re-seal the border to Americans given the backdrop of rising Covid cases and deaths from the virus in the U.S.

The Liberal leader said the Canadian border was closed to nonessential foreign travelers throughout the pandemic and only reopened recently to fully vaccinated Americans. Trudeau added that Covid's fourth wave is almost entirely among the unvaccinated population.

"The risk of welcoming in people who are fully vaccinated is minimal, but we continue to monitor it carefully," he said in response to another question on the border measures.

Trudeau also argued that his government has been coordinating closely with the Biden administration on the border restrictions. For example, he said the cooperation has ensured that essential trade has continued to flow through the pandemic.

He also noted the asymmetrical nature of the border restrictions. Canadians, even the unvaccinated, have been permitted to fly to the U.S. since the start of the pandemic.

Bloc Québécois Leader Yves-François Blanchet, Trudeau's main opponent in much of Quebec, described the Liberal leader's border management approach Friday as "recurrent laxism." But Blanchet declined to say whether Trudeau should re-close the frontier to Americans.

Reaction to the U.S. extension: The U.S. decision Friday was met with frustration on both sides of the border.

For months, families separated from loved ones, business leaders and lawmakers have been upping the pressure on President Joe Biden to loosen measures or at least provide a detailed plan.

"The failure to make opening the U.S.-Canada border the priority that it should be is a huge mistake. It is beyond disappointing; it is hurtful both at a human and economic level," Rep. Brian Higgins (D-N.Y.) wrote on Twitter after the announcement.

The Canadian Chamber of Commerce said it was disappointed by the decision on the land border, especially since Canadians can fly to the U.S.

"This creates confusion for travellers when all our members repeatedly tell us they are seeking predictability," Mark Agnew, senior vice president of policy, told POLITICO in an email. "This also distracts from the efforts that should be put into developing interoperable digital health credentials.”

What's next: Earlier this week, Ted Sobel, the Department of Homeland Security’s attaché to Canada, offered some insight as to why the U.S. extended the border restrictions the last time, back in July.

The spread of the Delta variant and its unknowns “loomed large” in the late-July decision to keep the U.S. land border closed to discretionary travel, he said Monday during a panel appearance.

Sobel said officials have also kept a close eye on public-health conditions in the U.S. — from rates of vaccination, new infections and hospitalizations — as well as the Covid circumstances in other countries.

A key to the process is determining which policy decisions will stand up to the pandemic’s volatility, he said.

“Certainly, our ability to resist the spread of any newly introduced carriers of Covid really does affect our ability to not just make the decisions, but make sure that the decisions we make are sustainable,” Sobel said during a panel discussion at the annual summit of the Pacific NorthWest Economic Region.

“It doesn’t do anybody good to announce one thing one month and then have to reverse it because the situation is changing very rapidly.”