The opposite of the phrase "be of assistance" can be "be uncooperative," "be unhelpful," "be unresponsive," or "be unsupportive." When someone is uncooperative, they may refuse to lend a hand, make excuses, or show a lack of willingness to help. Unhelpful behavior shows an uninterested or unwilling attitude towards assisting a person. Being unresponsive means not responding to requests for help or showing disinterest in solving a problem. Unsupportive behavior relates to a lack of emotional or practical support for someone in need. These antonyms indicate actions that hinder instead of help individuals.