An ETIAS visa, which is good for three years, enables Americans to enter the bloc as often as they like.
The move to introduce a new type of a visa was taken by the bloc in order to improve security and "to avoid any further problems with illegal migration and terrorism," according to the ETIAS website.
The Schengen Area is a zone which includes 26 EU states (plus Norway) where no internal borders exist and people are allowed to move freely.
This comes after in June last year, the EU parliament held a vote supporting the Commission's decision to impose visas on American nationals.
In 2016, the European Commission urged the US authorities to provide the bloc's member-states Bulgaria, Croatia, Poland, Romania and Cyprus the right to travel visa-free just like the majority of EU citizens; this has led to a drawn-out dispute between the US and the bloc.