Asians have surpassed Hispanics as the United States' largest group of new immigrants.

The Pew Research Center found that the number of Asian immigrants grew from 19 percent of all new immigrants in 2000 to 36 percent in 2010.

Incoming Hispanic immigrants fell from 59 percent in 2000 to 31 percent.

Up to 11 percent of illegal immigrants in the United States are Asian while about 75 percent are Hispanic, according to the analysis, which combined government data with its own polling.

The findings come amid fierce debate over the nation's immigration policies.

President Barack Obama announced on Friday he was halting deportations for young illegals.

The US Supreme Court is also expected to rule this month on Arizona's controversial law requiring police to check the immigration status of detainees.

While the economy is paramount for voters, illegal immigration is being hotly debated ahead of the November election.

Some have questioned the timing of Obama's announcement.

The policy change also complicated efforts by his Republican challenger, Mitt Romney, to fashion an immigration platform of his own.

Much of the debate has centered on Hispanics, a highly visible group and the nation's largest ethnic minority population.

Experts said there was no single answer for why Asian immigrants surpassed Hispanics, but the sluggish US economy probably played a big role.

"Illegal immigration responds quickly to economic conditions" and the US recession was a likely damper, said Jeanne Batalova, a demographer at the Migration Policy Institute.

US immigration policy tends to favour skilled labour and students, something that works to the advantage of immigrants from Asian countries that have a deep focus on education, she and other immigration experts said.

Gabriel "Jack" Chin, an immigration expert and law professor at the University of California at Davis, said the atmosphere created by changes in immigration laws in certain states also was likely a factor.

"I don't think there's any question that discrimination has had some effect on Hispanic immigration," said Chin.

Pew's report is valuable, Chin said, because "it points out that all undocumented, unauthorised migrants are not Mexican or Hispanic. There are plenty who are Asian or from other countries in the world."

WEALTHIER, MORE EDUCATED

Pew's 225-page report paints a comprehensive picture of an Asian population that swelled over the past 50 years.

"The modern immigration wave from Asia is nearly a half century old and has pushed the total population of Asian American... to a record 18.2 million in 2011, or 5.8 percent of the total US population," researchers wrote.

That gain is up from less than one percent in 1965 and includes those who have immigrated or were born in the United States.

There are 52 million Hispanics in the United States, more than 38 million blacks and nearly 198 million whites, according to the report.

Other government data has also shown the United States on track to have ethnic minorities as its "majority" population rather than whites.

Pew's findings show all Asians in the United States, not just recent immigrants, are a well-educated group that tends to have more college degrees, a higher annual household income, and greater wealth than the overall US population.

While immigration experts said newcomers to the United States tend to hail from less economically developed countries, there is a demand for the highly skilled labor that many Asians can offer.

Eighty percent of all Asian Americans are Chinese, Indian, Japanese, Korean, Filipino or Vietnamese, the report said.

The nonpartisan research group's findings are based on US Census data and economic data as well as the center's poll of more than 3500 Asian Americans between January and March.

The Pew poll's margin of error is plus or minus 2.4 percentage points.

- Reuters