"So we're not going to have a definitive answer to 'Do we get fooled again?' either until North Korea once again defects from the process or until it becomes clear that they are refusing to reopen or resume it", said Scott Snyder, senior fellow for Korea studies at the Council on Foreign Relations, a USA think tank.
North Korea is said to have a strong mining sector, contributing around 34 per cent of the country's GDP. In contrast, Moon's right-wing opposition is splintered, and the Liberty Korea Party is weighed down by his impeached predecessor Park Geun-hye, whose approval rating is a miserly 13%.
Shares in Butan Industrial dipped further off their recent highs following Trump's get-together with Kim Jong Un, closing around 10% lower.
In talks that continued until 2008, North Korea halted nuclear activities again and disabled some key elements at its main nuclear complex in return for security, economic, and energy benefits.
A task force has been also launched to prepare for possible tour programmes in the North by South Korean tourists, according to the Korea Tourism Organisation.
Whether Trump is willing to make that move is unknown. According to estimates from the South Korea-based Bank of Korea, the North's economy grew 3.9 percent in 2016, its best year in over a decade, although it is hard to collect accurate data on the country.
North Korea is more endowed with natural resources, ranging from coal to rare earths, which would complement South Korea's industrial output. The U.S. also agreed to lift economic sanctions and provide heavy fuel oil to operate North Korea's electric power grid. Political change and eventual reunification of North and South Korea can't be imposed from the outside, he said. From 2009 to 2013 official North Korean trade tripled, from about $1 billion to over $3 billion.
The challenge of rebuilding North Korea's infrastructure would be huge. The country's main exports are coal and textiles.
Life expectancy is 10 years lower in North Korea (69.2 years vs. 79.3 years in South Korea).