The Texas GOP senator's campaign announced Thursday that he's invited Trump to join a rally planned at the Capitol soon to pressure lawmakers on opposing the nuclear agreement. The rally is sponsored by Tea Party Patriots, Center for Security Policy, and the Zionist Organization of America. 

"We are thankful for all their hard work on this effort and will have more details on time, date, and location as they are finalized," the Cruz campaign said. 

Trump hinted that an event was coming earlier Thursday, telling supporters at a campaign event in South Carolina: "I think we're going to do something next week or the week after about the Iran pact" in Washington. 

"We're going to have a tremendous crowd come out," Trump promised.