(REUTERS) - There was such excitement when Al Jazeera America launched in 2013, pledging to deliver hard-hitting journalism from the United States, coast-to-coast.

But just two and a half years after its high-profile launch - and many hundreds of millions of dollars later - the channel's parent company says it's shutting down its US operations by the end of April, citing economic challenges in the American media market.

Al Jazeera bought Al Gore's Current TV in January of 2013 for US$500 million (S$719.5 million) to compete with US networks like CNN, MSNBC and Fox News.

But it always faced an uphill battle to build a loyal US audience, given it was under the patronage of the Qatar government.

The network almost immediately hit challenges, as cable distributors like Time Warner Cable and AT&T argued they had contracted with Current TV - not Al Jazeera.

The company says it will now expand, instead, its existing international digital services in the US - as consumers ditch traditional media outlets and move to smartphones and tablets for their news.