Wa alaikumussalam wa rahmatullahi wa barakaatuh, Ramadaan Mubaarak.
I don't know if there is a difference of opinion on this matter, but from what I have read, it is forbidden even if they are non-Muslims.
See:
http : //islamqa . com/en/ref/78494/
I have to type the link like that because otherwise it doesn't allow me to post it.
Relevant part:
With regard to your question, you should note that it is not permissible for you to offer food to anyone to eat during the day in Ramadaan, unless he has an excuse that allows him not to fast, such as one who is sick or is travelling. There is no differentiation between Muslims and kaafirs in this matter. The Muslim who is not fasting is commanded to fast, so he is sinning by not fasting. Enabling him to eat and drink during the day in Ramadaan is helping him in sin and transgression. The command to fast and all other rulings are also addressed to the kaafir, but before that he is required to utter the Shahaadatayn (the twin declaration of faith) and enter Islam. On the Day of Resurrection the kaafir will be punished for his kufr and for the laws of Islam that he did not follow, so his punishment in Hell will be increased.
Al-Nawawi (may Allaah have mercy on him) said:
The correct view which is followed by the majority is that the minor issues of sharee’ah are addressed to the kuffaar, and silk is haraam for them as it is haraam for Muslim men. End quote.
Sharh Muslim, 14/39.