A Korean-American human rights activist who was tortured while being detained in North Korea for 43 days from late 2009 has written an open letter to US President Donald Trump urging him not to launch military strikes against the reclusive nation because of the potential loss of innocent life.

In the letter, Robert Park called on Trump to consider the lives of millions of North Koreans who are not part of Kim Jong-un’s regime and who have merely had the misfortune to be born in a country that has been under the control of the same dynastic dictatorship for more than 70 years.

Similarly, the blameless people of the South would inevitably be subjected to the fallout of any conflict on the Korean peninsula, whether that were a conventional conflict or a nuclear war, Park said.

“I sincerely beg – whatever you decide to do in concert with South Korean authorities and the international community – that none of the general people of both North and South Korea would ever get hurt,” Park wrote. “Koreans have already endured and sacrificed far too much.”

Park’s appeal comes as tensions in the region continue to rise. A US nuclear submarine is docked in Busan in South Korea and the USS Ronald Reagan, along with its accompanying strike fleet, is about to start exercises with the South Korean navy off the peninsula. A second aircraft carrier battle fleet, centred on the USS Eisenhower, has left San Diego for the western Pacific, while US B-1 Lancer bombers again this week carried out training missions off the coast of Korea with South Korean and Japanese aircraft.

WATCH: Trump tells Tillerson: don’t waste time talking to North Korea

North Korea nuclear crisis: time to panic yet?

The anniversary this week of the founding of North Korea’s Workers’ Party passed without provocation from Pyongyang, but there are reports the regime is preparing to launch another long-range ballistic missile to show it can strike mainland US targets.

And while Trump and Kim continue to use their militaries to posture, there seems to be little progress in diplomatic efforts to reach a peaceful solution to the crisis. That is a concern to Park, who was detained in North Korea after illegally entering the country on Christmas Day 2009 to protest against the regime’s human rights situation.

Tortured in detention, Los Angeles-born Park was released in February 2010, and is a founding member of the non-partisan Worldwide Coalition to Stop Genocide in North Korea. Park lives in South Korea but, concerned for his personal safety, he stays out of the spotlight while he campaigns for the rights of the people of the North.

Park’s letter suggested he fears the threat of a military clash is at its greatest since the Korean war ended in 1953.

“Thank you for taking the time to hear my plea for peace on the Korean peninsula,” the letter begins.

“It has been brought to my attention that persons who have advised you and are within your administration profess to be Christians.

“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 unchristian to countenance indiscriminate killings of these who are among the world’s most suffering.”

Park said as many as 400,000 North Koreans practice their faith in secret, despite the risks.

Another dilemma, he said, was the location of North Korea’s political prisoner camps, which sit near facilities that produce or store the regime’s weapons of mass destruction. Political Prison Camp No. 16, for example, covers about 500 sq km close to the Punggye-ri nuclear testing grounds where North Korea in September carried out its sixth and largest underground atomic detonation.

Equally, he said about 10 million Koreans remained separated from their families by the demilitarised zone that bisects the peninsula.

What would China do if North Korea and the United States go to war?

“Therefore, it is my sincere and tearful prayer that you, Mr President, would take into serious consideration these excruciatingly painful and unresolved tragedies, while honouring the moral imperative to determine a peaceful resolution vis-à-vis the security predicament,” Park wrote.

Clearly not an apologist for the Kim regime, Park used the letter to propose an alternative method to bringing down the dictatorship.

He asserted that recent defections of “elite” members of North Korean society showed that even those with privilege have had enough of Kim and are ready and willing to rise up against his tyranny.

“There is a thoroughly workable and peaceable solution to the North Korea crisis,” he wrote. “It centrally involves reaching out to the general populace of North Korea in sympathy and supporting their internal unseating of Kim Jong-un – one individual.

“The overwhelming majority of North Koreans hope and yearn to be reunified with the South, to live in a gentler and more egalitarian society and to bid adieu to Kim Jong-un,” he said. “Those who suggest otherwise, Mr President, unfortunately retain an inaccurate assessment of the overall situation on the ground.”

Park added an “earnest, wholehearted and tearful plea” to Trump. “Mr President: please unconditionally preserve the lives of both North and South Korea’s general population. Under no circumstances – if cornerstone international laws, norms and principles professing to safeguard these innocents’ most sacred right to life contain any substance – can the loss of their lives be countenanced.”