CNN says Secretary Rubio just struck a deal with Bukele to accept deportees from the United States regardless of nationality, including US citizens, as long as we pay to house them in his prison.
That is not what is happening. The agreement is to use El Salvadorian prisons instead of US prisons for prisoners. El Salvador said they would be willing to accept any prisoner, regardless of nationality. The US citizens would not be deported, but imprisoned in another country. However, it is not clear if the US will use El Salvadoran prisons for US citizens, only foreigners or not at all.
I literally just pulled the first definition. It is not my dictionary, but Google's. If you don't like the first definition that comes up, that is on you, not me.
Second, it is not even clear that any US citizens will be shipped off. Bukele is just offering it and Trump said he isn't sure if it will happen.
Third, US citizens are able to serve their sentence in a foreign country if they so choose since 1977 [1]. Obviously this situation is not the same, but the US does send its citizens to foreign prisons sometimes.