Washington: Some 11.5 million foreigners are living in the United States without proper immigration documents, according to estimates released by the US Department of Homeland Security.

The figures, as of January 2011, show little difference from the 11.6 million figures published in 2010.

"These results suggest little to no change in the unauthorised immigrant population from 2010 to 2011," DHS said in a report on Friday.

It is unlikely that the number of these migrants increased after 2007 "given relatively high US unemployment, improved economic conditions in Mexico, record low numbers of apprehensions of unauthorized immigrants at US borders, and greater levels of border enforcement," the report said.

Mexicans represented 59 percent of all the undocumented migrants, followed by 14 percent from three Central American nations six percent from El Salvador, five percent from Guatemala and three percent from Honduras.

China, the Philippines, India, South Korea and Vietnam all accounted for two percent each.

DHS said 31 percent of the unauthorised migrants defined as all foreign-born non citizens who are not legal residents entered the country before 1995, 55 percent entered between 1995 and 2004, and only 14 percent have entered since 2005.

"Most unauthorised residents either entered the US without inspection or were admitted temporarily and stayed past the date they were required to leave." it added.