The U.S. State Department Friday shot down a recent report that Islamic State fighters-- aided by violent drug cartels-- are operating training bases near the U.S. southern border to smuggle terrorists into states like Texas.

A Judicial Watch report released Tuesday that cited an unnamed Mexican Army officer and a Mexican police inspector who identified the locations of two bases, raising new fears that the fight with ISIS is closer to the U.S. than previously thought.

But a State Department spokesman told Fox News Friday that U.S. authorities have worked closely with Mexican officials to investigate the allegation, and both countries have determined the claim to be “unfounded.”

“The United States and Mexico work together on counterterrorism and border security to protect the citizens of both of our countries from the threat of terrorism and violent extremism,” the spokesperson said in an email.

The report suggested that one of the two bases discovered is as close as eight miles from Texas, in a town west of Juarez. Mexican authorities found possible evidence -- plans written in Arabic and Urdu -- last week in the town of "Anapra," the sources said. These sources told the watchdog that "coyotes" who work for drug cartels assist in smuggling terrorists between Fort Hancock, Texas, and other undisclosed locations.

“We are concerned about the spread of ISIL (Islamic State) outside of Iraq and Syria, and take any threat to the United States seriously.  ISIL has clearly stated its intent to spread its violence into other parts of the globe.  This is something our intelligence community is watching diligently,” the spokesperson said.

The Mexican border has long been seen as a potential vulnerability. FoxNews.com reported last summer that social media chatter shows ISIS is aware of the porous border, and are “expressing an increased interest” in crossing over to carry out a terrorist attack.

Fox News' Edmund DeMarche contributed to this report