No. An inheritance, regardless of amount, is tax free to the heir. It does not matter whether the person who died was a U.S. citizen or a foreign national.
A written determination issued to a taxpayer by the IRS that interprets and applies the tax laws to the taxpayer’s specific set of facts. A letter ruling advises the taxpayer regarding the tax treatment that can be expected from the IRS in the circumstances specified by the ruling. It may not be used or cited as precedent by another taxpayer.