Now you are referring to them as "hostile states," not as enemy states. Israel is faced with enemy states. You should also keep in mind that parliamentarians from the US who make visits usually do so as part of their parties' delegations, and not as individuals who represent no one besides their domestic constituencies. No domestic minority has the right to engage in foreign affairs of their own. Ultimately, this is a domestic issue, not an international one.
First refugees travelling on Hungarian bus arrive at Austrian border (Reuters)
from the article: Arab MKs: Bid to bar trips to enemy states is 'racist'