Khawaja Asif said the government would not hesitate to bomb militant hideouts or send forces into the tribal areas if the Pakistani Taliban did not abide by the ceasefire announced last weekend.
Mr Asif said: "It will not take months now. We'll have to march in the month of March.
"If there is a ceasefire, it has to be complete. Without that, we just can't afford to have talks with the Taliban."
Pakistan fears the end of the US combat mission in neighbouring Afghanistan this year could energise a resilient insurgency straddling their shared frontier.
Mr Asif added: "If in the post-withdrawal period the Afghan Taliban become stronger and carve out an area of influence next to our border, that's a scenario we should even avoid thinking of."