By David Shepardson and Steve Scherer

WASHINGTON/OTTAWA (Reuters) -United States land borders with Canada and Mexico will remain closed to non-essential travel until at least June 21, the U.S. and Canadian governments said on Thursday.

The restrictions were first imposed in March 2020 in response to the COVID-19 pandemic and have been extended in 30-day increments.

“We’re working closely with Canada & Mexico to safely ease restrictions as conditions improve,” the U.S. Homeland Security Department said on Twitter.

It remains unclear whether restrictions will be lifted before the busy summer travel season. U.S. officials are also weighing whether to loosen air travel restrictions that prevent much of the world’s population from visiting.

Border towns and businesses have been hit hard by a lack of cross-border traffic. Many U.S. lawmakers have urged loosening the restrictions or providing a timetable for resuming normalized travel. They say Americans who own property in Canada cannot maintain their homes.

U.S. officials said discussions with Canada and Mexico had been unable to win agreement on ending the restrictions.

Mexican Foreign Minister Marcelo Ebrard said on Tuesday he hoped that U.S.-Mexican border restrictions imposed due to the coronavirus pandemic would be lifted before summer ends in September.

Canada has also been requiring air passengers arriving in Canada to be tested for COVID-19 before a hotel quarantine period.

Canada lags the United States on vaccinations against the coronavirus, and much of the country has been fighting a third wave of the pandemic with school and business closures, though matters have improved in recent weeks.

Air travelers to Canada are required to have had a test within three days of departure, and then again on arrival. If the airport text comes back negative, they can finish a 14-day quarantine at home.

(Reporting by David Shepardson in Washington and Steve Scherer in Ottawa; Editing by Chizu Nomiyama and Howard Goller)