Immigration will drive the population of the United States sharply upward between now and 2050, and will push whites into a minority, projections by the Pew Research Center showed Monday.

"If current trends continue, the population of the United States will rise to 438 million in 2050, from 296 million in 2005," an increase of nearly 50 percent, the study by the Washington-based think-tank said.

More than 80 percent of the increase will be due to immigrants arriving in the country and their US-born children, who will make up nearly one in five Americans by 2050 compared with one in eight in 2005, it said.

Whites, who currently make up around two-thirds of the US population, will become a minority (47 percent) by 2050, the report said.

The Hispanic population, currently the largest minority group, will triple in size and double in percentage terms from 14 percent in 2005 to 29 percent in 2050, the report said.

The Asian population will roughly double in percentage terms, from five percent to nine percent, while the black population will remain static at around 13 percent.

The projections are based on trends over the past 50 years, during which legal and illegal immigration have played an increasing role in US population growth, the report said.

From 1960 to 2005, new immigrants and their US-born descendants accounted for 51 percent of population increase, and for 58 percent from 1980 to 2005, the report said.

But, the report warned, "possible future changes in immigration policy" could impact the projections.

Illegal immigration has become a top issue in the race for the US presidency, especially among Republican candidates, most of whom favor of a crackdown.