South Korean national security adviser Chung Eui-yong, center, finishes making a statement March 8, 2018, at the entrance to the West Wing of the White House in Washington, D.C.
Michael Reynolds, EPA-EFE

South Korean national security adviser Chung Eui-yong stood outside the White House on Thursday evening and announced President Trump will meet with North Korean leader Kim Jong Un by May to talk about ridding the Korean Peninsula of nuclear weapons.

We've heard Trump call Kim "Rocket Man" and hurl other insults, while Kim has referred to Trump as a "dotard," but what's been the relationship between the U.S. and North Korea over the years? Let's break it down.

Residents from Pyongyang, North Korea, and refugees from other areas crawl perilously over shattered girders of the city's bridge, as they flee south across the Taedong River to escape the advance of Chinese communist troops Dec. 4, 1950.
Max Desfor, AP

How it all began

After Japan surrendered to the Allies — U.S., Britain, France, Australia, Canada, New Zealand, India, the Soviet Union and China — at the end of World War II, the Korean Peninsula was split into two "zones of occupation," with North Korea occupied by the Soviet Union, and South Korea occupied by U.S. troops, according to an article in The Conversation, written by Ji-Young Lee, a professor at American University.

A North Korean attempt to unify the peninsula in 1950 led to the Korean War, in which the south and north, backed by China, fought to a basic draw after millions of Koreans and Chinese died, along with more than 50,000 Americans. Technically, the two Koreas are still at war. 

The USS Pueblo, shown underway at sea, was captured late Jan. 22, 1968, by North Korean patrol boats who took it into Wonsan. There were 83 men aboard the vessel. This photo was released Jan. 23, 1968, by the U.S. Department of Defense.
AP

Decades of tension

Divided officially in 1953 by the Korean Demilitarized Zone at the 38th parallel, North Korea and South Korea have been at odds ever since. The Korean War left feelings of anger and hatred on both sides because many families were forcibly separated, some never to be reunited, according to an article on the World Economic Forum's website.

In 1968, during the height of the Vietnam War, North Korean forces attacked and captured the USS Pueblo, a Navy intelligence vessel, in what's now called the "Pueblo incident." The ship's 83 crew members were seized and imprisoned. One died before the crew was released 11 months later. 

President Barack Obama and South Korean President Park Geun-hye inspect an honor guard during a welcoming ceremony at the presidential Blue House in Seoul on April 25, 2014.
Kim Hong Ji, AFP/Getty Images

How have recent U.S. presidents treated N. Korea?

While George W. Bush described North Korea as part of an “axis of evil,” his successor, Barack Obama, kept up an attempt at dialogue mixed with sanctions, according to the WEF article. 

Obama said in 2014 that Washington would stand "shoulder to shoulder" with South Korea in its rejection of a nuclearized North Korea and believed sanctions were the way to force North Korea to disarm. Addressing a joint news conference alongside then-president South Korean Park Geun-hye in April 2014, Obama said threats by North Korea will get it "nothing except further isolation" from the global community. 

Obama conceded that additional sanctions may have limited impact. "We are not going to find a magic bullet that solves this problem overnight," he said. "We can't waver in our intention. We have to make sure that, in strong concert with our allies, that we are continuing to press North Korea to change its approach," he said.

President Donald Trump and North Korean leader Kim Jong Un
Jim Watson, AFP/Getty Images

What's been Trump's approach?

President Trump has taken a hard line. His use of apocalyptic imagery in threatening "fire and fury" against North Korea represented some of the most bellicose language uttered by any president since World War II. Speaking at his Bedminister, N.J., golf club in August, Trump warned: "North Korea best not make any more threats to the United States. They will be met with fire and fury like the world has never seen."

President Trump speaks about North Korea at the Trump National Golf Club in Bedminster, N.J., Aug. 8, 2017.
Nicholas Kamm, AFP/Getty Images

Trump's statement, in response to reports that the communist regime had developed a warhead that could be mounted on a ballistic missile, mirrored a North Korean propaganda machine that once threatened to turn the South Korean capital into a "sea of fire." 

It's all about the nukes

Can the U.S. convince Kim to abandon his nuclear program? Experts are skeptical. Kim has said repeatedly that he needs a nuclear-strike capability to deter any military moves by the U.S. to topple his dictatorial regime. 

There also is a political motive behind Kim's drive. The nuclear program is "a point of great national pride," said Sheila Miyoshi Jager, a professor at Oberlin College and author of Brothers at War: The Unending Conflict in Korea. "The fact that North Korea has been able to join the exclusive nuclear club, and that it rankles a big superpower like the United States ... is a huge rallying point of pride for the North Korean people, which Kim needs to shore up his regime," she said. "Why would Kim ever want to give this up?"

Trump and Kim have traded insults, including taunting each other about whose "nuclear button" is bigger.

More: Five unforgettable presidential summit meetings

More: Trump agrees to first-ever meeting with North Korea's Kim Jong Un

More: What you need to know about potential U.S.-North Korea talks

More: What do we really know about North Korea? Here are 10 fascinating facts

More: North Koreans tease nuclear weapons concessions. Should Trump believe them?

Contributing: Jim Michaels, Oren Dorell and Kim Hjelmgaard