Claim: Donald Trump and South Korean President Moon Jae-in agree the US President deserves credit for peace talks with North Korea.

Verdict: Only the historical record will reveal what influenced these talks, but evidence suggests it was the South Koreans who encouraged dialogue with the North, along with pressure from Chinese enforced sanctions.

Leaders of North and South Korea are expected to meet 27 April, for their third leaders' summit since the Korean War armistice was signed in 1953. Then in May or June, Donald Trump is expected to meet North Korean leader Kim Jong-un, for the first ever meeting between a leader of the North and a sitting US president.

After mounting tension and military threats traded between the US and North Korea, the historic talks may bring about a de-escalation of hostilities, as well as a peace treaty to end the 68-year Korean War.

On 4 January 2018, US President Donald Trump tweeted: "With all of the failed 'experts' weighing in, does anybody really believe that talks and dialogue would be going on between North and South Korea right now if I wasn't firm, strong and willing to commit our total 'might' against the North. Fools, but talks are a good thing!"

South Korean President Moon Jae-in said publicly too that President Trump deserved big credit for bringing about talks to discuss peace with the North. "It could be a resulting work of the US-led sanctions and pressure."

Image copyright Getty Images

US-led sanctions enforced by UN

Since North Korea detonated its first nuclear test in 2006, the US and a number of allies imposed sanctions on North Korea. As well, the United Nations Security Council passed nine rounds of sanctions on North Korea - many of these proposed by the US.

Over the years, these sanctions became more strict. The initial UN sanctions in 2006 banned the supply of heavy weaponry, missile technology and luxury goods. By December 2017, the UN sanctions restricted oil imports, metal, agriculture and demanded the deportation of North Koreans working abroad.

While these most recent sanctions were US-led under the administration of President Trump, it may be China's recent enforcement of UN sanctions that hit North Korea hardest. China accounts for more than 90% of North Korea's trade, and while the Security Council member voted in favour of the UN sanctions against their long-time ally, they rarely upheld those, reports the Council on Foreign Relations. However, in this past year, China appears to have enforced the sanctions.

Having already proved his military capabilities, Mr Kim is now turning his attention to economic growth, says Dr John Nilsson-Wright, a senior research fellow at Chatham House. So while the sanctions didn't stop Mr Kim from developing weapons, this latest development could hinder his economic plan for the long term.

Image copyright Huw Evans picture agency Image caption In a campaign to abolish nuclear weapons, activists wear masks of President Trump and Mr Kim, in front of the American embassy in Berlin

Tough talks and threats of military action

On 2 January 2018, President Trump tweeted: "North Korean Leader Kim Jong-un just stated that the 'nuclear button is on his desk at all times'. Will someone from his depleted and food-starved regime please inform him that I too have a nuclear button, but it is a much bigger and more powerful one than his, and my button works."

On 23 September 2017, President Trump tweeted: "Just heard [the] foreign minister of North Korea speak at [the] UN. If he echoes [the] thoughts of Little Rocket Man, they won't be around much longer."

To compare, President Obama, in 2014, warned North Korea that "we don't use our military might to impose these things on others, but we will not hesitate to use our military might to defend our allies and our way of life".

In 2016, President Obama told CBS News North Korea was "erratic enough" and "irresponsible enough that we don't want them getting close".

"We could, obviously, destroy North Korea with our arsenals. But aside from the humanitarian costs of that, they are right next door to our vital ally, the Republic of Korea," he added.

President Bush, for his part, labelled North Korea part of the "axis of evil."

America has for years used words and threats of military might.

Image copyright Getty Images Image caption Kim Yo Jong (top right), sister of the North Korean leader, attends the Olympics in South Korea, along with President Moon Jae-in (bottom left)

The influence of South Korean engagement

Two presidents prior to Moon Jae-in, Lee Myung-bak (2008-2013) took a hard-line approach to North Korea. The next president, Park Geun-hye (2013-2017), promised engagement with the North, a strategy that ended in early 2016 following missile and nuclear tests.

In his inauguration speech, Mr Moon said he would "do everything I can to build peace on the Korean peninsula".

This is a return to the Sunshine Policy of Presidents Kim Dae-Jung (1999-2003) and Roh Moo-Hyun (2003-2008), who were the only other two South Korean presidents to meet North Korean leadership - during the Inter-Korean Summits of 2000 and 2007. Kim Dae-jung won a Nobel Peace Prize for his efforts.

"More credit should go to the South Koreans, because they actually made sure to have the North Koreans come to the Olympics and that was organised very very quickly," said senior lecturer Dr Virginie Grzelczyk, of Aston University. "The invitation to have the North Korean delegation and Kim Jong-un's sister…has been really critical to organise the summit that we are going to see at the end of the week."

So why is the South giving credit to Trump?

South Korea is acting strategically, says Dr Grzelczyk, to bring the Americans around to a place of dialogue "because both Koreas have at some point, been perplexed and concerned by American policy".

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