Europe has reopened to visitors from 14 countries but not the US, where some states that pushed hard to reopen their economies are now in retreat because of a surge in confirmed coronavirus infections.
The European Union's decision came a day after Arizona governor Doug Ducey closed bars, gyms, cinemas and water parks and officials in Republican and Democratic strongholds mandated the wearing of masks.
The EU extended its ban on visitors from the US, China, Russia, Brazil and India, where infections are running high.
Britain dropped out of the EU in January and maintains its own rules, requiring travellers to go into 14-day self-quarantine.
US President Donald Trump suspended the entry of most Europeans in March. Americans make up a large share of Europe's tourism industry, with more than 15 million travelling to continent each year.
The news was a blow to revenue-starved shopkeepers hoping for a summertime boom.
"Americans were 50% of my clientele," said Paola Pellizzari, who owns a jewellery shop in Paris and heads its business association.
"We can't substitute that clientele with another."
The Louvre museum is scheduled to reopen on July 6. Americans used to be the largest single group of foreign visitors to the home of the Mona Lisa.
"When I returned after lockdown, five businesses had closed," Ms Pellizzari said.
"As days go by and I listen to business owners, it gets worse."
Sharmaigne Shives, an American who lives in Paris, said she hopes her countrymen can turn things around soon.
"Paris isn't Paris when there aren't people who really appreciate it and marvel at everything. I miss that," she said.
"Seriously, I feel the emotion welling up. It's so sad here."
Coronavirus has been blamed for over 500,000 deaths worldwide, including about 130,000 in the US, where the number of confirmed infections has rocketed over the past month to around 40,000 per day, primarily in the south and west.