Trump knows what nationalism means, and if he didn’t the first time he promoted, people clued him in. Did he condemn those that hold troubling views. No - he doubled down again and again.
In the context of what Hill said - his remarks during a Wednesday meeting of the Committee on the Exercise of the Inalienable Rights of the Palestinian People in observance of the International Day of Solidarity with the Palestinian People. He accused the Israeli government of “normalizing settler colonialism" and called for a "free Palestine from the river to the sea," a remark that got applause from participating diplomats.
He didn’t explicitly say “wipe Israel from the map” but he knew his audience - just like Trump knows his. It is all about signaling support for causes while avoiding accountability for what you say. It is dangerous if you don’t hold people accountable in these cases.