(CNN) - As the Obama administration deals with a surge of unaccompanied and undocumented children from Central America cross the U.S. southern border, Rep. Michele Bachmann said Tuesday that immigrants have "invaded the United States" by the thousands since the spring.
"Since April, 300,000 to 500,000 foreign nationals at their election have invaded the United States," the Minnesota Republican said on CNN's "Crossfire."
Bachmann said that after spending Monday at the National Counterterrorism Center, "our own government is extremely concerned about who is coming across the southern border."
Bachmann, a member of the House Intelligence Committee, added: "We have foreign nationals that are coming across the southern border from countries like Yemen [and] Iran."
Crossfire "co-host" Van Jones pressed Bachmann on what to do with the children crossing the border, asking if she was referring to the children as "invaders."
Bachmann again repeated that thousands of foreign nationals had crossed the border illegally since April, but did not specify further.
Bachmann is one of number of Republicans who have come down hard on President Barack Obama over how he's handling the issue of undocumented immigrants entering the country.
Some Democrats have also criticized the administration over its handling of the influx of undocumented children but many argue that the youths deserve their day in court
Republicans, on the other hand, say more money should be "targeted" to quickly deport immigrant children.