Israel has recently been cold towards the US because of our stance on Iran. Iran is an existential threat towards Israel, and Iran has been playing a big part in the fight against ISIS as an effort to further Iran's goal of puppeting Iraq (which is pretty much complete at this point), gaining influence over Syria, Eliminating the Kurds, and strenghtening it's alliance with Russia. All of this is at complete odds with Israel, so of course Israel doesn't want to play a big part in the fight against ISIS as long Iran and Assad are playing big parts in it.

Also, Israel isn't an "occupying power", it holds territory that was conquered in a war that was declared against Israel, not the other way around. Anyone who says shit like this, during a time when relations with Israel, our only ally in the region, are already hurting is a complete liability to the white house. We should be doing everything we can to re-assure our ally who is extremely uncomfortable with our close relationship with Iran/russia/assad in the fight against ISIS. Things like this, and refusing to end the Iran deal, are not helping whatsoever.