I am a Master's student having bad grades. Can I gain a PhD?

I am a Master's student and have finished one semester out of four semesters. I have got C grade for twice but my goal is doing PhD in the US. Shall I quit the program and restart a new Master's or keep going on my current Master's? I am studying social science subject in Europe. I have 4 modules more to go in the first year... No publishing.