Story highlights Donald Trump continued his bashing of Ted Cruz on Monday, saying he was "dishonest" and stole the Iowa caucuses

Trump spoke in South Carolina, just days before the primary February 20

Hanahan, South Carolina (CNN) Donald Trump escalated his battle with Ted Cruz on Monday, calling the Texas senator "unstable," threatening a lawsuit and urging the Republican National Committee to "intervene."

"One of the ways I can fight back is to bring a lawsuit against him relative to the fact that he was born in Canada and therefore cannot be President," Donald Trump said in a statement. "If he doesn't take down his false ads and retract his lies, I will do so immediately. Additionally, the RNC should intervene and if they don't they are in default of their pledge to me. "

The billionaire businessman later held a press conference in which he said he "never ever met a person that lies more than Ted Cruz."

Trump continued to heap criticism on Cruz in an interview with CNN's Jim Sciutto Monday afternoon on "The Lead," saying that with "guys like Ted Cruz -- it's all talk and no action."

"He's a very bad guy. He's a very nasty guy. He's got no endorsements from any senators who he works with. He'll never be able to unify anything," Trump said of Cruz.

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