You can eat unlimited amounts of veggies and lots of lean protein, like meat, chicken, fish, low/no fat dairy, etc. Drink water; no soda or other sweetened drinks.
Watch your portion sizes and be sure to eat only one portion of everything, except non-starchy veggies. Avoid peas, potatoes, corn because they are starchy.
So...any diet to lose 3kg and fat from belly??
That's a starvation diet that has no nutritional value whatsoever. It makes no sense and I'd never condone it.