WASHINGTON (Reuters) - U.S. land borders with Canada and Mexico will remain closed to non-essential travel until at least April 21, the U.S. government said on Thursday. The 30-day extension is the second announced under President Joe Biden and comes as U.S lawmakers in northern border states have urged lifting the nearly year-old restrictions to address the COVID-19 pandemic. In a notice Thursday, the Department of Homeland Security said the three countries have all “determined that non-essential travel ... poses additional risk of transmission and spread of the virus.” Canadian Public Safety Minister Bill Blair confirmed the extension of restrictions on Twitter. Canada has shown little interest in lifting the restrictions and last month imposed new COVID-19 testing requirements for some Canadians returning at land crossings. On Jan. 26, the U.S. government began requiring nearly all international air travelers to get negative COVID-19 test results within three days of travel but has no similar requirements for land border crossings. The Biden administration has spent weeks reviewing whether to impose COVID-19 testing requirements for land border crossings but has not issued new requirements. In an executive order in January, Biden directed U.S. officials to “immediately commence diplomatic outreach to the governments of Canada and Mexico regarding public health protocols for land ports of entry.” U.S. lawmakers say Americans who own property in Canada cannot maintain their homes. Border towns and businesses have been hard hit by the lack of cross-border traffic. Hundreds of thousands of people cross the U.S.-Mexico border daily, and Mexico has extremely limited COVID-19 testing capacity, U.S. officials say. Representative Tom Massie of Kentucky said at a March 2 hearing a vacationing Kentucky family recently tested positive in Mexico for COVID-19 and could not return to the United States on a flight. “They flew to Tijuana, walked across the border to the United States, got on an airplane in San Diego and then returned to Kentucky,” Massie said.