U.S. Secretary of Homeland Security Jeh Johnson testified before the Senate Appropriations Committee on the U.S. government in Washington, Nov. 12, 2014. Johnson said Monday that the number of undocumented migrants entering the country had dropped significantly. Reuters

The secretary of the U.S. Department of Homeland Security on Monday defended President Barack Obama's immigration policies. During a speech in Texas, Jeh Jonson, who is charged with overseeing the U.S.-Mexico border, said the number of illegal migrants entering the country has dropped significantly and that 2015 is on track to have the lowest apprehension total since 1972.

"It's now much harder to cross our border illegally and evade capture than it used to be, and people know that," Johnson said during a speech about border security at Rice University's Baker Institute for Public Policy on Monday in Houston, according to the Houston Chronicle.

The number of people apphrended at the Southern border this fiscal year -- compared with last year -- has fallen 34 percent, according to KPRC in Houston. The number of apprehensions is used as a barometer for the amount of people attempting entry into the U.S., Johnson said. "The bottom line of all this is, in recent years, the total number of those who attempt to illegally cross our southwest border has declined dramatically, while the percentage of those who are apprehended has gone up," Johnson said, according to KPRC. The number of apprehensions through eight months this fiscal year was 213,145.

The reduction in undocumented migrants entering the country is significant, especially considering last summer's influx of migrants -- many of whom were children -- from Central American countries. An estimated 68,000 unaccompanied minors, many fleeing violence, entered the United States last summer. From 2013 to 2014 the number of unaccompanied children crossing the border increased by 90 percent, according to the Migration Policy Institute. Border patrol was flooded and could not handle the crisis. In response, the Obama administration took measures including running an ad campaign to deter more migrants from coming, adding border patrol agents, expediting the undocumented immigrants' court cases and adding two detention centers to house children and mothers waiting for the outcome of their cases, reported the Chronicle.

The drop in apprehensions in 2015 could perhaps signal that the Obama administration's policies were effective in dealing with the crisis. Still, Johnson said they “are not — repeat, not — declaring mission accomplished,” according to the Washington Times.

The detention facilities have also recently come under criticism, especially from Democratic leaders. Democratic representatives in the Senators and House have written letters to Johnson criticizing the family detention centers. Johnson said Monday that the government was working on alternatives to detention but did not elaborate further, the Chronicle reported.

Johnson later commented that he felt the U.S government would ultimately win in a Texas-led lawsuit against an executive order signed by Obama that would shield an estimated 5 million undocumented immigrants from deportation and grant them work permits, according to the Chronicle.