Americans rely on their mobile devices for online news far more than desktop or laptop computers, building on a trend that began several years ago, a survey showed Wednesday.

The Pew Research Center report found 57 percent of US adults often get news from a smartphone or tablet compared with 30 percent from a PC.

The share of Americans who often get news on a mobile device is more than double the 21 percent who did so in 2013, the first time Pew asked this question.

The percentage who often get news on a desktop or laptop computer has remained relatively stable during this period.

Younger adults are far more likely than others often to use a mobile device for news - 72 percent in the 18-29 age bracket compared with 38 percent among those aged 65 and older.

The seniors were more likely to use a PC for news than the younger group, by a margin of 34 to 23 percent, Pew found.

The survey comes as online giants such as Google, Facebook and Apple step up with new ways to deliver news and curb the spread of viral misinformation on their platforms.

The platforms have also come under increasing pressure from struggling legacy news organizations to offer a better share of digital ad revenues that stem from news stories.

Facebook last month began rolling out its dedicated "news tab" with professionally produced content in the latest move by the social network to promote journalism and shed its reputation as a platform for misinformation.