The United States has extended the closure of its land borders with Canada and Mexico to non-essential travel such as tourism through Sept 21 despite Ottawa's decision to open its border to vaccinated Americans, Reuters reports.

The latest 30-day extension by the Department of Homeland Security (DHS), came after Canada said in July it would start allowing in fully vaccinated US visitors starting Aug 9 for non-essential travel after the Covid-19 pandemic prompted a lengthy ban that many businesses have called crippling.

"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," DHS said on Twitter.