PARIS — European lawmakers and business groups voiced mounting criticism of the Biden administration on Tuesday, after the White House said its restrictions on international travel would remain in place for the time being.

Whereas vaccinated U.S. tourists have been allowed to return to much of Europe for weeks, most Europeans continue to be unable to travel to the United States under a ban that was first imposed by President Donald Trump in March 2020.

The White House said Monday that the continuation of existing travel restrictions was attributable to concerns over the highly transmissible delta variant. A number of European nations, including Spain, Britain and France, have recently seen a rise in cases linked to that variant.

But the delta variant has long been in the United States, already accounting for the majority of new known cases, and many European nations are now starting to outpace the United States in vaccinations: 49 percent of Americans are fully inoculated, compared with more than 46 percent of European Union residents. Both have similar per capita coronavirus case numbers.

E.U. critics of the U.S. approach have also pointed to less restrictive rules that are in place for travel from many other nations to the United States, including from countries with weak health systems and high coronavirus case numbers.

As vaccinated American tourists are traveling back and forth for their summer holidays in Paris or Rome again, European allies or partners of the Biden administration are finding it increasingly difficult to defend the U.S. stance, which critics say has divided European families and posed serious challenges to businesses.

“I think reciprocity makes sense,” said Radoslaw Sikorski, who chairs the European Parliament’s delegation for U.S. relations. “We have opened up the Schengen zone to American travelers, and the U.S. has not done that to our citizens.”

Some experts said the cautious U.S. approach may be based on legitimate public health concerns about particular European countries. But in countries such as Germany, where the ratio of fully vaccinated people is now higher than in the United States, the White House announcement prompted disbelief among many.

There is “no logical scientific explanation” for the U.S. approach, an editorial published by RND, one of Europe’s largest local news providers, concluded Tuesday, describing the practice as a political scandal and evoking a “wall in the middle of the Atlantic.”

“From a public health perspective, the entry ban makes little sense if Americans can travel and catch the virus, and given that tests could provide a reasonable solution,” said Tobias Kurth, a German public health expert.

The White House announcement could dampen the political will in Europe to convert U.S. vaccination cards to E.U. digital vaccine certificates, especially if the bloc’s countries view the decision as a breach of trust, said Jacob Kirkegaard, a senior fellow at the German Marshall Fund.

“It’s not going to make it any easier at the E.U. level because there is a ‘you scratch my back, I scratch yours’ dynamic — a degree of trust or political goodwill that plays a role here,” he said.

Damien Regnard, a conservative French senator, said he similarly fears that the U.S. stance may prompt a rethink within the E.U. about U.S. travelers entering the bloc.

“If the U.S. becomes red, well, that’s it,” he said, referring to a traffic light system used by some European countries to classify a country’s epidemiological situation.

“We just want some kind of fairness and logic,” Regnard said. The U.S. approach is “making life impossible for people, and it’s going to be terribly costly,” he added.

European legislators appealed to Biden administration officials in person last week, arguing that the similar rates of infection and vaccination on each side of the Atlantic should mean open travel for the inoculated — in both directions. Sikorski said he and his colleagues met with members of the National Security Council and the State Department and asked that the United States match Europe’s stance on American travel.

It’s about more than tourism, Sikorski added. “You should remember there are thousands of Europeans stranded in the United States who have not seen their families in over a year, and this is a real hardship for a lot of people,” he said.

Roland Lescure, a lawmaker with French President Emmanuel Macron’s party, said around 100,000 French citizens based in the United States have been separated from their families because of the restrictions.

“The problem is French residents in the U.S. who do not have a green card or a U.S. passport. If they go back to France, they don’t know if it will be possible for them to come back to the U.S.,” Lescure said.

Citizens of other E.U. nations have faced similar challenges, prompting German Chancellor Angela Merkel to raise the issue during a meeting with President Biden in Washington two weeks ago.

Because of their reliance on foreign exports, German businesses have been hit particularly hard by the U.S. restrictions.

In a statement Tuesday, the country’s association of mechanical engineering businesses, VDMA, called the White House decision “absolutely incomprehensible.”

The association said many of its members have struggled to receive exemptions from the restrictions for their employees, hampering transatlantic trade at a time when both the United States and the E.U. are eyeing quick economic growth to make up for losses caused by the pandemic.

“There is no justification for the exclusion of European business travelers,” said VDMA representative Ulrich Ackermann.

Constanze Stelzenmüller, a senior fellow at the Brookings Institution, said she has some sympathy for the continued ban, especially in the weeks following the recent European Football Championship, when stadiums were packed with thousands of maskless fans in what health officials called “a recipe for disaster.”

But the restrictions are too broad and fail to account for the intertwined economies of the transatlantic corridor, Stelzenmüller said.

One example: people like herself. Stelzenmüller, a German citizen who works in D.C., has not been able to go home or travel to Europe for work since the onset of the pandemic. It’s been maddening for her personally, she said, but she warned that it could have a broader impact on economic relations.

“It’s about keeping our economic relationship working,” Stelzenmüller said. “By not finding something more acceptable and adaptable than a blanket travel ban, we are damaging this economic interdependence.”

Thebault and Ariès reported from Brussels. Karla Adam in London and William Glucroft in Berlin contributed to this report.