US Homeland Security Secretary Kristi Noem has released a social media video filmed inside a controversial mega-prison in El Salvador, thanking the country and its president for "bringing our terrorists here and incarcerating them".

Secretary Noem was in the country to tour the facility, where US officials recently sent 238 Venezuelans.

Homeland Security Secretary Kristi Noem toured El Salvador's notorious Terrorism Confinement Center on Wednesday, where hundreds of alleged criminal illegal aliens are being held after the Trump administration deported them earlier this month.

Noem toured the prison with the Salvadoran Minister of Justice, Héctor Gustavo Villatoro, before meeting with El Salvadoran President Nayib Bukele. Noem’s visit is part of a three-day trip that will also see her travel to Colombia and Mexico.

US Homeland Security Secretary Kristi Noem on Wednesday visited the high-security El Salvador prison where Venezuelans who the Trump administration alleges are gang members have been held since their removal from the United States. The tour included two crowded cell blocks, the armory and an isolation unit.

Noem’s trip to the prison — where inmates are packed into cells and never allowed outside — comes as the Trump administration seeks to show it is deporting people it describes as the “worst of the worst.”