"I believe we have to get ISIS," Trump said, referring to the so-called Islamic State terror group. "We have to worry about ISIS, before we can get too much more involved" in Syria.
"I don't like Assad at all, but Assad is killing ISIS. Russia is killing ISIS, and Iran is killing ISIS. And those three have now lined up because of our weak foreign policy."
Trump accused Clinton and her successor as secretary of state, John Kerry, as well as President Barack Obama of making Iran "strong" and "into a very powerful nation and a very rich nation, very very quickly."
"With Iran, who you made very powerful with the dumbest deal I've ever seen, the Iran deal, with the $1.7 billion in cash, which is enough to fill up this room," Trump said without completing the sentence.
When Clinton noted that she had left office as secretary of state before the nuclear agreement with Iran, which resulted in the release of Iranian funds frozen by the United States, Trump was dismissive, saying she was probably in touch with Obama at the time.
Correction: This story was revised to correct that Clinton had left office as secretary of state before the agreement with Iran was reached.