Is it permissible to give charity despite knowing that I owe delayed Zakat?

Zakat must be paid immediately upon the completion of the hawl (one lunar year), and it is not permissible to delay it when possible. Whoever delays it after being able to pay has disobeyed and becomes liable. Delayed Zakat is considered a debt. If one's wealth is not sufficient to repay the debt and also give voluntary charity, then voluntary charity is not permissible because Zakat is an obligatory right.