United Kingdom

and the purpose of this is to remove the unwanted foreigners from British jurisdiction and make them Somebody Else's Problem. And also, it is explicitly being sold by the government as a deterrent - "you'll never be allowed to settle in this developed country, you'll be sent to a developing country with a dodgy human rights record, a GDP per capita of about $900, and the highest population density in Africa". The Rwandan president may also be one of the few people who'd agree to this.