Is Zakat obligatory on money saved to repay a debt to the state, when it has reached the nisab and a full hawl has passed over it, but it has not reached half of the required repayment amount?

If you do not have other money, in excess of your needs, that can be used to pay off the debt, then there is no Zakat due on the saved amount. This is because debt, according to the majority of scholars, precludes Zakat on hidden wealth. However, if you possess other money, in excess of your needs, that you can spare and use to pay off the debt, then you must pay Zakat on the saved amount if it reaches the nisab (minimum threshold) and a full year has passed on it. Ibn Qudamah mentioned that debt prevents Zakat on hidden wealth if it consumes the nisab or reduces it, and one has no means to pay it off except for the nisab itself or what is indispensable.