The allegations make no sense (as this was not a secret at the time such a conversation would have been had, unless you have info that this conversation took place far before it was public knowledge) and seems at most Zarif is repeating what the Israel Finance Minister Israel Katz said and either confusing it with Kerry or that comment had come up in a conversation with Kerry. To suggest that Kerry somehow leaked classified info would actually require something more then this. Not sure what needs defending here.
In any case, if you are saying Kerry should be removed over a pathetically weak allegation then clearly you are of the opinion that Trump should have been impeached and convicted over his giving over info to the Russians about Israel in a major breach.
Frankly, this is a witch hunt and the Republicans should be ashamed for their despicable attempts to promote lies and smear people. Not unsurprising as this is what they always do.