Warren Buffett tackles Trump in defending value of immigrants

Billionaire investor Warren Buffett used his annual letter on Saturday to laud immigrants and their contribution to the growth of the US economy amid President Donald Trump's anti-immigrant stance.

"Americans have combined human ingenuity, a market system, a tide of talented and ambitious immigrants, and the rule of law to deliver abundance beyond any dreams of our forefathers," he wrote in the letter to shareholders of his massive Berkshire Hathaway conglomerate.

The annual missive from the 86-year-old investor -- the world's third-wealthiest person, according to Forbes magazine -- is pored over for clues to the thinking of the "Oracle of Omaha", who lives and works in the Nebraska city.

Buffett steered clear of any mention of Republican President Donald Trump, who took office on January 20. He had supported Democrat Hillary Clinton in her bid to win the White House.

The letter came as the country grapples with a sharp controversy over Trump's anti-immigrant policies and his crackdown on the estimated 11 million undocumented people living in the country.

The letter accompanied Berkshire Hathaway's release of 2016 fourth-quarter and full-year earnings.

The company reported a net profit of $6.3 billion in the October-December period, a gain of nearly 15 per cent from a year ago.

For all of 2016, net profit came in at $24.1 billion, slightly lower than the prior year.

Berkshire, which has stakes in Kraft Heinz, Coca-Cola and a number of other companies, and recently invested in Apple, has benefited from the Wall Street rally after Trump's election.

Berkshire gained $27.5 billion in net worth during 2016, Buffett said.