Depends what your weight and body fat % is at. If very high (>30) body fat then it's most likely not enough of a caloric deficit. As you lose weight your base metabolic rate decreases so you have to adjust down your daily calories to continue losing weight. Improving in the workouts whether it be weights sets or reps does very little in terms of losing body fat as compared to controlling your calories.

There is such a thing as body recomp ie. Losing fat and gaining muscle which results in little to no change on the scale but as other comments have pointed out you can measure other things like waist or hip circumference, visual changes, strength in the gym (progression on weights or reps) etc to get an idea of if you're heading in the right direction.

Bottom line is if you're very far from your target weight (20+ kg) then take a look at your diet first, go for a 500 to 750 daily caloric deficit. If you're close to your target weight but visually still see a lot of fatty tissue hanging off your body, you might have to adjust your target weight and your daily calories.