When someone says "calling halt to," they mean to put an end to something or to stop it completely. However, there are several antonyms to this phrase that can be used depending on the context. If someone wants to encourage the continuation of an activity, they might say "encouraging progress" or "promoting advancement." On the other hand, if someone wants to delay or pause a process, they can use antonyms like "stalling," "postponing," or "procrastinating." There are also antonyms like "allowing to proceed" or "facilitating progress" that indicate the opposite of calling a halt to something. Depending on the situation, one can choose an appropriate antonym to convey their message effectively.