Jseal,

The president is not only an elected official he is the head of state and can only be removed by resignation, death or after he has been impeached.

In Australia and the UK (Canda too I suspect), the prime minister who is the head of government is an elected member of the lower house (ie in US the house of Reps). A Prime Minister can be removed by his own party by electing another leader.

The President is not a member of either legislature to my knowledge.

There is a quite a different system in the US than in Australia or the UK.