New daily coronavirus cases in the United States soared past 50,000 for the first time Wednesday, as the World Health Organization delivered a grave warning that the global pandemic is accelerating.

Restaurants, bars and beaches in the world's worst-hit nation closed from California to Florida, as states reeling from yet another surge in the deadly virus braced for Independence Day festivities.

Global infections have hit their highest level in the past week, WHO data showed, with chief Tedros Adhanom Ghebreyesus saying new cases topped "160,000 on every single day."

The grim milestone came as the European Union left the United States, Brazil and Russia off its final list of nations safe enough to allow residents to enter its borders.

With more than 52,000 new COVID-19 cases in the United States alone in the past 24 hours, according to a Johns Hopkins University tally, several US states imposed 14-day quarantines on visitors in the buildup to the long weekend's July 4 celebrations.

California suspended indoor dining at restaurants in Los Angeles and several counties, while New York scrapped plans to allow restaurants to seat customers inside from next week. 

Stable genius Donald Trump reiterated his belief that the contagion will "at some point... sort of just disappear, I hope."

But the US leader who has yet to be seen in public wearing a face mask during the pandemic added he would have "no problem" doing so. 

EU eases its travel ban

The rollbacks came as the European Union reopened its borders to visitors from 15 countries.

The bloc hopes relaxing restrictions on countries from Algeria to Uruguay will breathe life into its tourism sector, choked by a ban on non-essential travel since mid-March.

Travellers from China, where the virus first emerged late last year, will be allowed to enter the EU only if Beijing reciprocates.

And Brazil - which has suffered the most deaths globally for the last week, and is the second-worst affected country overall - was excluded entirely.

It topped 60,000 total fatalities Wednesday, after suffering 1,000 deaths in just 24 hours.

However, with over 10 million known infections worldwide and more than 500,000 deaths, the pandemic is "not even close to being over", the WHO warned.

Data provided by the UN health agency for the seven days from June 25-July 1 showed the highest number of new daily cases ever recorded came on June 28, when over 189,500 new cases were registered worldwide.

According to the United Nations, the coronavirus crisis could cost global tourism and related sectors from $1.2 to $3.3 trillion in lost revenue.

Greece, which has suffered fewer than 200 virus deaths, has seen its economy hit hard by lockdowns and travel restrictions -- all but ending its lucrative tourism season before it began.

Romanian Cojan Dragos was "the first tourist" in one Corfu hotel after driving there with his wife and daughter.

"We have the whole hotel just for us," he said. 

Separately, Spain and Portugal held a ceremony as they reopened their land border.