North Korean leader Kim Jong-un was told by his father to never give up nuclear weapons, US President Donald Trump’s son-in-law and senior adviser Jared Kushner reportedly told a Trump biographer.

According to Doug Wead’s book “Inside Trump’s White House,” Kushner discussed with Wead the letters that Kim and Trump wrote to each other, the Washington Times reported Tuesday.

“You can see from these letters that Kim wants to be friends with Trump, but his father told him never to give up the weapons. That’s his only security,” Kushner was quoted as saying in the book, excerpts of which were obtained by the US daily.

“Trump is like a new father figure. So, it is not an easy transition.”

Kim Jong-un has officially said on several occasions that the denuclearization of the Korean Peninsula was a deathbed injunction from his grandfather Kim Il-sung and father Kim Jong-il.

Wead, who served as a senior White House staffer for two presidents, was given exclusive access to Trump, his family and senior staff for the book to be published next month, the Washington Times said.

Wead also said in his book that Kim hates the word “hostage,” and asked Trump not to use the word when they met alone.

Wead’s book describes how Trump negotiated the release of three US hostages from North Korea in May 2018 ahead of his first summit with Kim Jong-un. In June 2017, North Korea released comatose US college student Otto Warmbier, who died shortly after his return.

The book also includes Trump’s account of his first face-to-face conversation with former US President Barack Obama in the White House Oval Office after Trump won the election in November 2016.

Trump thought Obama was “stupid” when the outgoing president confided that he had refused to talk with Kim Jong-un because he was a dictator, according to the book.

“Barack Obama told me that my greatest problem, when I became president, was the possibility of war with North Korea. … In fact, privately, he said, ‘You will have a war with North Korea on your watch,’” Trump was quoted as saying in the book.

When Trump asked him if he had called Kim, “Obama said, ‘No, he’s a dictator,’ as if that in itself explained everything.”

Wead wrote: “Two years later, Trump was still amazed by that conversation. And then he concluded, out loud, to all of us in the room. ‘Stupid.’”

Trump told reporters on Monday that Obama had tried to call Kim 11 times, but Kim rejected his calls out of “lack of respect.” A former National Security Council spokesman under Obama said the incident Trump described had never happened.

By Kim So-hyun (sophie@heraldcorp.com)