#military aid

I recently read a statement by Trump that the US continues to sell NATO weapons to Ukraine, whereas the previous administration provided them for free. I am interested in whether this practice of selling weapons during a conflict complies with international law?

Germany plans to transfer long-range missiles to Ukraine. Does this contradict international law and what consequences could it have for Ukraine?

The Minister of Foreign Affairs of Spain, José Manuel Albares, stated that the country will allocate 1 billion euros for the purchase of military equipment for Ukraine. I want to know if these funds are subject to any international control regarding their use?