US citizens travelling to Europe will need to obtain a visa from 2021, the European Union (EU) has said.
The new European Travel Information and Authorization System (ETIAS) visa will be required for all US citizens who want to enter any of the 26 Schengen-zone countries.
The Schengen area is formed of 26 countries where there are no internal borders, allowing people to move freely between nations.
Currently US citizens do not need a visa for trips to Europe that last under 90 days.
The EU said the new restrictions were drawn up "to avoid any further problems with illegal migration and terrorism" but stressed that the ETIAS visa, once obtained, would be valid for three years.
"The ETIAS visa for Americans is a multiple-entry visa with few restrictions in order to promote tourism while maintaining a high level of international security," a spokesperson for the EU said in a statement.
Most people living in the EU are able to travel to the US without a visa but this does not apply to citizens of Poland, Cyprus, Romania, Croatia and Bulgaria.
Citizens in these countries require a visa for US visits.
The EU has repeatedly pushed to remove the restrictions and in 2016 the EU Commission released a report calling for US authorities to lift the requirements to ensure "full visa reciprocity".
To obtain the new ETIAS visa US citizens will require a "valid passport, a credit or debit card and an email account", a spokesperson for the EU said.
Minors will still be able to enter the Schengen area without an ETIAS visa and will only need their passports to travel.
