Louange à Allah.
Yes, it is permissible to give charity to non-Muslims in order to soften their hearts towards Islam, with the hope that they will become Muslim, whether it is zakaah or voluntary charity. With regard to other purposes, it is permissible to give them voluntary charity but it is not permissible to give them zakaah, because Allaah says (interpretation of the meaning):
“Allaah does not forbid you to deal justly and kindly with those who fought not against you on account of religion nor drove you out of your homes. Verily, Allaah loves those who deal with equity”
With regard to zakaah, it is not permissible for a kaafir unless he is one whose heart is to be softened towards Islam, because Allaah mentions among those who are entitled to zakaah (interpretation of the meaning) “and to attract the hearts of those who have been inclined (towards Islam)” [al-Tawbah 9:60]. End quote.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him).