Store it somewhere safe and stable, that way if you're invaded the government in exile can still access the country's wealth to fund resistance and what-not, or at least keep the invaders from just taking it.
But it also means that if there is a regime change, the new government will have no money to run the nation, and will have to seriously harm the quality of life of the inhabitants to re-earn those savings through taxation.
It really seems like one option here is best for maintaining the status quo with the existing government, whilst the other is best for the people of the nation.
Source: all that stolen wealth in WW2.