B1签证申请延期i-539，还没有批下来，如果现有的签证I-
-Not have to. You are legal to stay during the I-539 pending.
还是可以在美国境内等待延期批下
-If it is denied before you leave, then your current visa on the passport is void. Thus, you need to apply for a new visa to reenter US in the future. If you leave US within one month after the case is denied, it should not affect your future visa application.
