That depends. For short enough pulses at a low enough duty cycle a 1/4W resistor would be fine, but if you want it to stand up to DC, it needs to be able to handle the max current continuously. Calculate its dissipation by V2/R, and take V as 0.7V which gives V2 of 0.5. Therefore a 0.33R resistor (for approx 2A trip current) would need to be at least 1.5W, and it would be preferable to make it at least 2W.
Consider paralleling higher value, lower wattage resistors to get the required wattage more cheaply. Caution: they will be a local hot-spot so you will need to derate them.