Marco Rubio implicitly criticized Donald Trump’s foreign policy platform Tuesday but said that he would not vocally condemn the presumptive Republican nominee in the months before the election.

“My policy differences and reservations about Donald’s campaign are well established. I’ve said them often, and I stand by those,” Rubio said during a foreign policy-focused event at the Hudson Institute in Washington. “That said, I don’t view myself as a guy who’s going to sit here for the next six months taking shots at him.”