Diplomatic roller-coaster that took the two leaders from rhetorical warfare

Donald Trump’s face-to-face with Kim Jong Un will mark a historic milestone in relations between Washington and Pyongyang - and cap a stunning about-face for the mercurial leaders who months ago were trading threats and insults.

Here is a look back at the 18-month diplomatic roller-coaster that took Trump and Kim from rhetorical warfare to the verge of the first summit between a sitting US president and a North Korean leader, set for June 12 in Singapore.

On January 2, 2017, weeks before taking office, then president-elect Trump vows that North Korea will never be allowed to develop a nuclear weapon capable of reaching US territory.

Early in his presidency, however, Trump sends out conflicting signals - in separate statements in April 2017, he described Kim as both a “madman with nuclear weapons” and a “pretty smart cookie” for managing to hold onto power at his young age.

On May 1, he stuns observers by declaring he would be willing - and “honored” - to meet the North Korean leader “under the right circumstances.”

Six months into Trump’s presidency, in July 2017, Kim conducts two intercontinental ballistic missile tests, and declares the entire United States to be within North Korea’s range.

MENTALLY DERANGED DOTARD

The following month, Trump threatens “fire and fury” if Pyongyang continues to threaten America, kicking off months of saber-rattling that set the world on edge.

Undeterred, Pyongyang weeks later test-fires a ballistic missile over Japan, and on September 3 carries out its sixth, “perfect” nuclear test, of a hydrogen bomb it claims can be mounted on a missile.

The US leader warns “talking is not the answer” to the stand-off with Pyongyang - although his administration still does not rule out a diplomatic solution.

On September 21, 2017, Washington unveils a raft of tough sanctions to curb North Korea’s nuclear and ballistic missile programme.

The announcement comes two days after Trump’s maiden speech to the UN General Assembly, in which he nicknames Kim a “Rocket Man” on a “suicide mission” and warns that if threatened, the United States will have “no choice but to totally destroy North Korea.”

In response, Kim brands Trump “mentally deranged” and a “dotard,” warning he will pay dearly for his threats.

After a new ICBM test from Pyongyang in November, Trump derides Kim as a “sick puppy,” while fears mount that the bellicose rhetoric could trigger a nuclear conflict.

As 2017 draws to a close, Kim boasts his missile arsenal can hit any city on the US mainland, warning in a New Year address that he has a “nuclear button” on his desk.

Three days into the New Year, on January 3, Trump retorts that his own nuclear button is “much bigger & more powerful.”

Pyongyang brands his outburst the “bark of a rabid dog.”

Following years of tensions, South Korea’s hosting of the Winter Olympics in February 2018 gives the neighbours a window to reopen communications, ushering in a spectacular Korean detente.