The United States has said it will maintain restrictions on international travel into the country, sidestepping European pressure, as cases of the Covid-19 Delta variant surge at home and around the world.

"We will maintain existing travel restrictions at this point," White House Press Secretary Jen Psaki told reporters.

"The more transmissible Delta variant is spreading both here and abroad," she said.

The Delta variant has contributed to a rise in Covid-19 cases in the US, overwhelmingly among unvaccinated people, and Ms Psaki said she expected the trend to continue "in the weeks ahead".

White House Press Secretary Jen Psaki spoke at a press briefing

Asked how travel restrictions would help, Ms Psaki said: "Yes, it is the dominant variant in the United States. That doesn't mean that having more people who have the Delta variant is the right step."

The US has restricted travel from the European Union, the UK, China and Iran for more than a year due to the pandemic, later adding other countries including Brazil and India.

The EU in June opened up to travellers from the US, typically requiring proof of vaccination or negative tests, under pressure from tourism-dependent nations such as Greece, Spain and Italy that feared another troubled year.

EU leaders have asked the US to show reciprocity, and President Joe Biden on 15 July said he would have an answer on the issue "within the next several days" after appeals by German Chancellor Angela Merkel.

The US makes widespread exceptions including for students, scholars, journalists and businesspeople, but European leaders have complained that the regulations inconvenience ordinary people and hinder transatlantic trade.