Christian singer/songwriter Sufjan Stevens has penned a letter addressed to "America", saying "Christ would be ashamed of us all," regarding the US treatment of refugees.

The letter was posted on Twitter on Monday.

Without addressing it directly, Stevens was clearly angling his letter at Trump's refugee-ban that has dominated the news in recent days. "There really is no such thing as an illegal immigrant, for we are all immigrants and refugees in a wildly changing world that is dominated by superfluous boundaries built by blood and war.

"We all come from somewhere else." 

Sufjan continued: "In short, our freedom and privilege are predicated on the unfortunate events that led to the decimation and alienation of others. This is what it means to be free. I regret to inform you that this is not God-ordained. But it is fact."

Sufjan had strong words regarding the US: "America, we will pay for our sins and the sins of our forefathers. Wait for it and embrace it – it will be a beautiful reckoning, a born-again experience."

The letter included several references to God. "Christ calls us to turn the other cheek," Sufjan wrote.

"The world is abundant. We are merely stewards. The life you live is not your own."

The artist called people to "eradicate barriers...listen and learn from each other, embrace each other, help each other, and work on transforming your mind and your behaviour in the direction of love. This is not New Age balderdash. This is what it means to be a human being."

The letter can be read here.