Are there some countries which apply a tax on bank transfers or?
Not sure that there is confusion. There are countries which apply taxes on capital remittances out of the country. Interestingly, reading around this, one of those countries is the United States, although weirdly the taxes are assessed at a state level rather than a Federal level (Oklahoma does it, and both Georgia and Iowa are considering it). It is normally a slightly softer form of exchange control. The tax that the person remitting from such a country pays is entirely separate from any tax which the person receiving it might have to pay as income or gift tax. Here is a useful link discussing taxation of remittances: Why taxing remittances is a bad idea