This is true, depending on your definition of terrorism. Especially in the practice of funding U.S.-friendly organizations in states with unfriendly governments you could argue this was an important U.S. foreign policy. Earlier this month Donald Trump claimed to have seen a video of a $400 million cash payment to Iran which coincided with the release of 4 American prisoners, suggesting a quid pro quo and decrying how the money will go towards funding terrorism. This allegation of quid pro quo was vehemently denied by the Obama administration, explaining that this payment had been carefully arranged for months, even as Trump repeated his claim.
Eventually Trump did acknowledge the video he claimed to have seen was not a ransom payment to Iran. But on Thursday these allegations once again came to the fore as the State Department stated the payment for Iran had been held as insurance until the prisoners were released. In other words, a low level form of coercive diplomacy. The payment was determined by the U.S. Supreme Court to settle outstanding U.S. debt to Iran.
John Kerry admitted in January that some of the money from Iran sanction relief will probably go towards funding terrorism. Portions of the payment will also most likely make its way into terrorist organizations. Is the suggestion then that the United States should not provide any money to foreign countries which could potentially go to terrorists? Including foreign aid? In that case the United States cannot give any money to almost any foreign governments.
Of course this may be what Trump wants. But Trump lost all credibility on this issue when he blatantly and obviously lied about it. This is also another situation in which he blatantly exposes his lack of foreign policy expertise and experience.