Leaders in Britain and France have tightened rules on wearing face masks in closed public spaces in an effort to curb the spread of coronavirus.
The UK government announced on Tuesday that masks would be mandatory in shops from July 24.
Prime Minister Boris Johnson had said on Monday that he thought "face coverings do have a real value in confined spaces," adding that the scientific evidence in favour of masks was growing.
"We are not out of the woods yet, so let us all do our utmost to keep this virus cornered and enjoy summer safely," health minister Matt Hancock said in the House of Commons on Monday.
Many had criticised the government's messaging after Chancellor of the Duchy of Lancaster Michael Gove said masks should not be mandatory.
But more countries are considering making face masks mandatory indoors, amid growing evidence that they protect people from infecting others and amid fear of a second wave of virus cases.
French President Emmanuel Macron said on Tuesday during a television interview that he would like to make masks mandatory in indoor public spaces from August 1 due to "weaknesses" in preventive measures.
"We do it for public transport and it works very well, but it's a bit erratic in closed public spaces," Macron said in a joint interview with French networks France 2 and TF1.
"I recommend to all our fellow citizens who are listening to wear a mask as often as possible when they are outside and of course when they are in a closed space," Macron added, stating that there would be government action.
French officials have recently warned of a slight increase in the number of cases, as people relax attitudes towards social distancing. The country has had more than 30,000 deaths due to the pandemic.
Some Spanish regions, such as Catalonia, have also recently made masks mandatory in an effort to curb transmission as cases begin to rise again.
Germany's Helge Braun, the Head of Federal Chancellery who coordinates pandemic response, told the AP that masks would likely remain compulsory for the coming months.
"Wearing masks is the smallest restriction one needs to accept to prevent infection," Braun said.