which amount is correct for Asset Creation - PO Rate or Invoice exchange rate

Hi,

We have PO in foreign currency created with one exchange rate and invoice associated with PO has another exchange rate. Cost of asset is created with exchange rate that is on invoice.

Therefore there is difference in amount and difference is exchange rate variance amount.I reviewed Doc ID 1339693.1 and indicates exchange rate variance amount should be part of asset. In such case which amount should be cost of asset?

thanks,