The filmmaker helped propel the Austrian actor to international fame by casting him in the 1984 sci-fi blockbuster, which went on to spawn a number of sequels, and they have kept in touch over the years.
The action man-turned-politician has been a regular in the headlines over the last few weeks, which have seen the star split from his wife Maria Shriver and confess to fathering a lovechild with his mistress, and Cameron has now revealed he has been supporting Schwarzenegger through the troubled time.
He tells Fox News, "He and I have spoken a lot. You have to stand by your friends. He and I have talked and I said, 'Look man, I stand by you.' He doesn't need my advice. He knows how to manage his image and to say what he needs to say, and he's going to say it on his own terms when he is ready. It is that simple."