MEXICO, May 21 (Xinhua) -- Despite anti-immigration measures, the United States has not managed to stem the flow of illegal immigrants to the United States, said the National Population Council Sunday.

    In a research report, the Mexico's state agency said the illegal immigration continues because immigrants are crossing in the United States from more physically dangerous areas and by the network operated by gangs of immigrant smugglers.

    From 1993 to 1997, Tijuana and Nuevo Laredo -- which are not distant from the U.S. cities of San Diego and Laredo respectively -- saw about 47 percent of illegal border crossings.

    Now only 26 percent of such crossings took place there because 20 percent illegal immigrants made their crossings now at Agua Prieta, El Sasabe and Sonoyta or over the desert in Sonora, where physical risks are much higher.

    In addition, more and more people were trafficked into the United States by the human smuggling gangs.

    According to statistics, a majority of undocumented immigrants from the Mexican states of Campeche, Chiapas, Oaxaca, Quintana Roo,Tabasco, Veracruz and Yucatan from 2001 to 2004 were transported into the United States by the gangs.

    The research agency recommended setting up a migratory deal to encourage orderly and legal migration.

    Last week, U.S. President, George W. Bush agreed to build a 600-km fencing along the U.S.-Mexico border while sending 6,000 National Guard troops there in what he described as a bid to fight terror and organized crime. Enditem