Pony and Uber are expanding their partnership across four additional European cities.

Uber is launching its first robotaxi service in Europe in a partnership with Silicon Valley autonomous vehicle (AV) builder Pony AI and Croatian mobility company Verne.

Robotaxi services are now available via Uber in select areas in Croatia’s capital city Zagreb, including the city centre.

The phased launch will see a licensed operator on board behind a wheel, before the vehicles are slowly rendered fully autonomous, the companies said. The service coverage is also expected to expand over time.

Pony and Uber are expanding their partnership elsewhere in Europe too, with plans for a fleet of 2,000 additional robotaxis spread across four cities. Details of the expansion plans have not yet been disclosed.