The world is gradually ending weeks of coronavirus confinement but one area remains firmly shut -- international borders, which few governments are yet daring to open.
Weeks ahead of what would be the start of the summer tourism season in the Northern Hemisphere, billions of dollars are at risk as travelers put off plans to go abroad.
"It's highly likely that international borders will remain partly closed until the pandemic is under control both in Europe and in the US, which is unlikely to happen at the same time," said Luigi Scazzieri, an expert on migration and transatlantic relations at the Centre for European Reform in London.
"But even once restrictions are relaxed, we should not expect things to just go back to normal. Potential quarantines and fear are likely to curtail tourism and, to a lesser extent, business travel," he said.
World air traffic plunged by 53 percent in March from a year earlier, the largest fall on record, according to the International Air Transport Association, the aviation industry's trade body.
Jobs are also on the line in restaurants, hotels and other sectors that depend on tourism.
- Coordinating the reopening -
Governments around the world say the reopening of borders will be determined through coordination -- a sharp contrast to the jumbled and piecemeal manner in which they were shut down.
US President Donald Trump in late January banned foreign visitors from China and in mid-March restricted travel from most of Europe.
His actions at first drew criticism for their unilateralism but much of the world has followed suit, including the European Union -- leading Trump to say he was vindicated.
Trump initially issued 30-day orders but they remain in place. Likewise, the EU measures are set to expire on May 15 but could be extended month to month.
The European Commission plans first to remove restrictions on movement between its member-states -- restoring a founding principle of the bloc -- before opening up to the rest of the world.
India, which sealed itself off entirely, had been due to reopen air traffic on May 3 but is widely expected to extend at least partial restrictions.
Asked this week when the United States would open up, Trump said it "depends on how long it's taken Europe to heal" -- although the United States has by far the most COVID-19 deaths of any country.
"It's tragic, but we'll be looking at what's happening in Europe and certainly we want to do that and they want to do it, too," Trump said.
- 'As fast as we can' -
The greatest worry for governments is a new wave of contagion sweeping across borders. The SARS-CoV-2 virus was first detected in the Chinese metropolis of Wuhan before spreading to virtually all corners of the world.
Secretary of State Mike Pompeo said the United States wanted to be "confident that people who travel in from those countries won't create a tremendous increased risk to the United States."
"We're going to do it as fast as we can and do so safely," he said of reopening borders.
In France, a diplomat said the priorities for reopening are schools and businesses followed by restaurants and cafes.
"Tourism and travel come later," the diplomat said.
If "staycations" become the norm in this year of pandemic, some wonder whether in the next few years, citizens of wealthy countries will begin to rethink their presumption that they can travel abroad at will.
"Borders will play a much larger role in our lives," Scazzieri said.
Some limited border movements have resumed. The Czech Republic has reopened its doors to certain commercial travelers and China has been negotiating bilateral accords with South Korea, Singapore and other countries to facilitate business travel.
The US-Mexico border remains largely open but with a ban on travel deemed non-essential, such as tourism and shopping, despite Trump's campaign vows to seal off the neighbor with a wall.
Trump, however, has curbed immigration to the United States during the pandemic.
Airlines have already taken stringent measures to prevent contagion, with US carriers offering masks, sealing all food containers and promising vigorous sanitization between flights.
Trump has proposed temperature checks and coronavirus tests for passengers arriving in the United States.
But with tests in high demand in the United States, systematic screening is a long way off -- and few expect a full return to normal until scientists find a vaccine.