Undocumented Guatemalans carry their belongings after crossing the Guatemala-Mexico border.2013 Getty Images
Illegal immigration to the United States appears to be on the rise again -- with immigrants from countries other than Mexico arriving in record numbers, according to a report released Monday.
The number of undocumented immigrants living in the U.S. rose from 11.3 million in 2009 to 11.7 million last year, according to a poll by the Pew Research Center's Hispanic Trends Project. This follows a sharp decline in undocumented immigration during the economic crisis, Pew said.
"As a whole, with the recession ending, the decrease in illegal immigration has stopped," Jeffrey Passel, a senior demographer at Pew, told The Associated Press. He added that immigration levels are closely tied to the strength of the U.S. economy and availability of jobs.
The number of undocumented immigrants peaked at 12.2 million in 2007, during the U.S. housing boom, according to the report. By 2009, after the recession, that figure had dropped to 11.3 million.
That reduction, in part, came as many Mexican workers who were already in the U.S. saw diminishing job opportunities and returned home.
Surges in immigration from Mexico, like those seen in the late 1990s and early 2000s, are not likely any time soon, said Douglas Massey, a professor of sociology and public affairs at Princeton University.
"Labor demand in the U.S. is still slack and wages are eroding, whereas there are jobs in Mexico, and wages are slowly rising as labor force growth there decelerates," Massey told the AP. "The pressures for mass migration are diminishing for now."
Although immigrants point to the U.S. economy as a major incentive, economic prosperity does not explain the demographics of the undocumented immigrant population.
Pressures in Central America that influence emigration are on the rise, namely drug-related violence and a poor rule of law in large swaths of the region. Honduras and Guatemala, for example, are among the countries with the highest homicide rates in the world.
In 2012, apprehensions of non-Mexicans at the Mexico-U.S. border nearly doubled the 2011 total, increasing to 99,000, according to the Pew report. While border apprehensions aren't an accurate measure of the number of illegal border crossers, they are indicative of changing flows.
According to recent Pew surveys, non-Mexican undocumented immigrants in the U.S. have come primarily from Central America, at roughly 15 percent of the total unauthorized immigrants. Together, South America, the Caribbean and other parts of Latin America represent 12 percent, and about 10 percent of unauthorized immigrants come from Asia.
The Obama administration said in May that unrest and poverty in many Central American nations are a large factor behind illegal immigration into the U.S.
Analysts have said that immigrants are shifting their migration paths from Arizona to southern Texas, due in part to that state's stronger economy as well as increases in Central American immigrants looking for a more direct route to the U.S.
Out of the six states with the highest undocumented immigrant populations -- California, Florida, Illinois, New Jersey, New York and Texas -- only Texas had continuous increases in illegal immigration. The remaining five states each increased to a peak in 2007 but then declined.
The Pew analysis is based on census data through March 2012. Because the Census Bureau does not ask people about their immigration status, the estimate on illegal immigrants is derived largely by subtracting the estimated legal immigrant population from the total foreign-born population. It is a method that has been used by the government and Pew for many years and is generally accepted.
The study warns, however, that with these types of estimates, there can be a large margin of error.
Al Jazeera and wire services