(CNN) President Donald Trump said Mexican cartels will "absolutely" be designated as foreign terrorist organizations, a move which could lead to tougher financial penalties and legal ramifications in the US against those involved.

Trump was asked Tuesday by conservative radio host Bill O'Reilly whether he'd "designate those cartels in Mexico as terror groups and start hitting them with drones and things like that."

"I don't want to say what I'm going to do, but they will be designated," Trump answered, adding that the US has offered the Mexican government "to let us go in and clean it out and (the President of Mexico) so far has rejected the offer. But at some point, something has to be done."

The President did not specify which cartels would be targeted. He said designating cartels would be justified over "losing 100,000 people a year" from drugs coming into the US and human trafficking.

When asked for more details on Trump's comments, a State Department spokesperson told CNN, "We don't discuss deliberations or the potential deliberations of our designations process."

Read More