Robert Park, a Korean-American missionary who was tortured after sneaking into Kim Jong-un's nation has urged the USA not to attack.
According to The Sunday Express, Mr Park was tortured after crossing into the secretive state on Christmas Day, 2009 to spread Christianity.
He only regained his freedom two months later, after allegedly being subjected to physical and sexual abuse.
In an open letter to Mr Trump, he predicted Christians would be the first to suffer in the event of an escalation in the conflict on the Korean peninsula.
He explained: "Please kindly be reminded that a large number of underground Christians are within North Korea.
"They are the most persecuted religious group in the world, according to multiple watchdogs of religious rights internationally.
"As I pray your team accepts upon deep reflection, it would be decidedly un-Christian to countenance indiscriminate killings of those who are among the people in the world who suffer the most."
The Open Doors Word Watch List currently rates North Korea the worst country in the world for Christian persecution.
Mr Park has spent years campaigning against North Korea's human rights record - especially towards the state's Christian population.
He urged Mr Trump to instead try and find a peaceful solution.
He added: "There is a thoroughly workable and peaceable solution to the North Korea crisis. It involves reaching out to the general populace of North Korea in sympathy and supporting their internal unseating of Kim Jong Un - one individual.
"This procedure must be accompanied by the freeing of all political prisoners - who are victims of crimes against humanity and possibly genocide - which can be achieved via the mediation of those North Koreans who assume interim administrative responsibilities in the immediate aftermath of Kim's indigenous and peaceful ouster.
"I've been praying through an outpouring of tears and wholeheartedly plead for you and your administration to remember the acute suffering and unparalleled victimisation of tens of millions of warm-hearted, gentle and benevolent North Koreans - who deserve compassion and require grace - and to please pursue a peaceable answer with regard to the security quandary."
Mr Trump's due to discuss North Korea's nuclear programme with Japan's prime minister - as he begins his first official tour of Asia.
