Yes.
Sounds good, but by what authority? Is there such a law??
A well run country would not send money to a terrorist organization, but since it has, the U.S. State Department and DOJ should declare that Hamas Leaders have committed Fraud and seek the impound of these funds where ever they can find them and of course, do a clawback of those funds. They should seek the arrest of these Hamas leaders through Interpol and send them to brussels for prosectuion by the world court. (If Mossad gets there first, well, that's OK too.)
To Brussels because We do not really want them here as a focal point for protest....Let them languish for 10-15 years awaiting prosecution and trial in Belgium. If released, Mossad can take care of things them.
This is of course what should happen, But this is Bumbling Joe & Barrack the Magic Brown Unicorn Show and it won't. (So between Ideal and Reality exists a cue for the Freek Chorus to start chanting: "It'll never happen! Call me when it happens! Nope, Nope, Nopers! etc."