Kilograms are mass, but pounds are weight. Therefore 0 kg = 0 slug, or 0 N = 0 lbs
I thought pounds could be used for either mass or force, and in modern usage just saying “pounds” usually refers to mass. Wikipedia seems to agree:
Sorry, perhaps this is a disciplinary difference. In engineering, physics, and biomechanics (my doctoral specialization), and from a unit standard perspective, the pound representing both mass and weight is a false equivalency born out of convenience. This is why the Imperial standard for mass is the slug, allowing for gravitational acceleration of a mass to equate to a force.