Covering estate tax on US assets for non-resident alien

Beneficiaries don't pay estate tax in the US; the estate does. What the beneficiary gets is whatever is left of the estate after the estate tax has been paid from the assets of the estate. The executor of the estate might need to sell some of the stocks in the brokerage account to raise the cash to pay the estate tax, and the money/stocks or whatever is left in the brokerage account passes to the beneficiary free of any kind of (US) tax. Furthermore, as per US law, the basis of the stocks inherited by the beneficiary is the market value of the stocks as of the date of your death and so the beneficiary only needs to pay capital gains on the stock to the extent that the stock price increased during the time the beneficiary held the stock; all (unrealized) gains that occurred during the time that the deceased held the stock before death are "forgiven" since the estate paid estate taxes on these gains. Now, what all this means to the beneficiary if the beneficiary is also a nonresident of the US is a whole 'nuther matter. Finally, all the above is for brokerage accounts that are not held as IRA or 401(k) accounts.