A more specific statement:
http://www.sichosinenglish.org/books/sichos-in-english/35/06.htm
...there was a time when we did not reach out to the gentiles to encourage them to observe the Seven Noachide Laws. In the old days any attempt to discuss faith in G-d with gentiles would invariably lead to danger and even mortal danger for Jews. So, except for a few exceptions, there was no opportunity to fulfill this mitzvah.
In our generation things are different. There is no danger involved in this activity, and to the contrary, such activity will increase the respect that the nations show us, for they will realize that Jews care not only about their own welfare but also about the good of all humanity and the whole world...
At any rate, with the confused nature of Noachism at this moment in history my own personal policy is to be open to all, but at the same time to exercise the greatest caution.