Google has announced four new features for its mapping services, including 3D cityscapes in Google Earth mobile apps.

The announcements are widely seen as a pre-emptive strike against Apple, which is expected to announce next week that Google Maps will not be used in the coming iOS 6 software release.

Apple is expected to announce at its WWDC 2012 developer conference next week that Google Maps will be replaced by its own data and services in the next version of its mobile operating system, according to the Guardian.

Google announced that the 3D cityscapes will be available in Google Earth mobile apps, and that the Android version of Google Maps will be able to download maps for offline usage in more than 100 countries within weeks.

The sophisticated 3D rendering makes use of an automated process to generate very detailed models from 45-degree aerial photos, for which Google has commissioned a fleet of aircraft.

The end result is zoomable, three-dimensional cityscapes, complete with top and side level views of buildings, streets and landscaping.

Ed Parsons, geospatial technologist at Google, said that while most 3D views in Google Earth have been in North America so far, it would be introduced in Europe, including the UK, in the next few months.

The internet firm plans to have 3D coverage for metropolitan areas with a combined population of 300 million people by the end of 2012.

Google also plans to expand its Street View concept to the great outdoors with an initiative called Google Street View Trekker, which is aimed at recording images of places that are not accessible to Street View vehicles.

Google is to expand its Map Maker tool to 12 new countries to help improve the accuracy of its maps, but this does not yet include the UK.

"There's a lot going on in mapping right now, and we wanted to be able to tell our story," said Brian McClendon, vice-president of engineering for Google Maps.

If Apple ditches Google Maps, experts say it would be a strike against Google, but the platform battle goes beyond Android versus iOS, according to the BBC.

After Google began charging for commercial use of its application programming interface (API) late last year, developers and publishers such as Foursquare and Wikipedia opted to use the free and volunteer-driven OpenStreetMap.

With 600,000 registered users, OpenStreetMap has also won the support of Microsoft, prompting analysts to speculate about a battle for the future of mobile computing between Apple, Google and Microsoft.