You have given me food for thought, bibo. Is it a basic human right to be able to move at will throughout the world regardless of national borders? Obviously the blanket answer is no, otherwise certain countries would be completely inundated and/or their security compromised. Are there special circumstances - such as family needs - that would mandate an exception? Let me think on that and get back to you. Again, I'd have to think in the aggregate here, not just your poor father's case. Wishing you and him well.
Mandi