North Korean leader Kim Jong Un said in his New Year’s address that his country was in the "final stages" of launching an intercontinental ballistic missile (ICBM). US President-elect Donald Trump, whose inauguration was set for January 20, said on Twitter: "North Korea just stated that it is in the final stages of developing a nuclear weapon capable of reaching parts of the US. It won't happen!"

North Korea tested its first ICBM — the Hwasong-14 — on US Independence Day. Kim reportedly told his scientists that "the US would be displeased" by the launch. This, he said, was because "it was given a 'package of gifts' ... on its 'Independence Day.'" Trump wrote on Twitter in response: "North Korea has just launched another missile. Does this guy have anything better to do with his life?"

Pyongyang tested its second Hwasong-14 weeks later. Experts estimated the new rocket could reach the US mainland. Trump lashed out at North Korean ally China, writing in a Tweet: "I am very disappointed in China. Our foolish past leaders have allowed them to make hundreds of billions of dollars a year in trade, yet they do NOTHING for us with North Korea, just talk."

Trump appeared to threaten swift military action against Pyongyang when he told reporters: "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." North Korea responded by threatening to fire a medium-range ballistic missile into the waters around Guam, a US territory in the Pacific Ocean. It did not follow through.

Pyongyang sparked international outcry when it test-launched a mid-range ballistic missile — the Hwasong-12 — over Japan. The UN Security Council unanimously condemned the test. Trump said in a White House statement: "Threatening and destabilizing actions only increase the North Korean regime’s isolation in the region and among all nations of the world. All options are on the table."

North Korea announced it had successfully tested its sixth nuclear weapon. Pyongyang said it was a powerful type of nuclear weapon called a hydrogen bomb and that it could be placed on top of a ballistic missile. Trump wrote on Twitter: "The United States is considering, in addition to other options, stopping all trade with any country doing business with North Korea."

In his first speech at the United Nations, Trump called North Korea a "rogue state" and said Washington "will have no choice than to totally destroy North Korea" if Pyongyang failed to stop its nuclear weapons program. Referring to Kim, he added: "Rocket man is on a suicide mission for himself and his regime." Kim called Trump a "mentally-deranged US dotard" two days later.

North Korea test-fired its third ICBM of 2017. Pyongyang claimed it was a new missile, the Hwasong-15, which was superior to the Hwasong-14 and could hit any target on the US mainland. The US urged allies, including Germany, to break diplomatic ties with North Korea. Berlin ignored the call. Trump also called Kim a "sick puppy."

Kim said in his 2018 New Year's address that the North had completed its nuclear weapons program and that a "nuclear button" was on his desk at all times. Trump wrote two days later on Twitter: "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 & more powerful one than his, and my Button works!"

South Korean President Moon Jae-in welcomed Kim's sister, Kim Yo Jong, at the presidential house in the South Korean capital. She handed a letter to Moon inviting him to meet the North Korean leader in Pyongyang. Tensions appeared to be thawing. Seoul and Pyongyang had already agreed to send a unified hockey team to compete at the Winter Olympics in Pyeongchang, South Korea.

South Korean National Security Adviser Chung Eui-yong led a delegation on March 5 to Pyongyang to discuss the potential for peace talks. The next day, Chung said both sides had agreed to hold a joint summit in April and set up a telephone hotline between the two capitals. He also said Pyongyang would agree to stop its nuclear weapons and missile tests if the US agreed to hold talks with the North.

Chung flew on to Washington, D.C. to speak with Trump. After the meeting, Chung told reporters the US president had agreed to meet Kim by May. Trump later wrote on Twitter: "no missile testing by North Korea during this period of time. Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!" Foreign leaders welcomed the historic breakthrough.

A week before the scheduled meeting at the border between South Korean President Moon Jae-in and North Korean leader Kim Jong Un, Moon said North Korea wanted "an end to the hostile relations" and had expressed a commitment to "complete denuclearization" of the peninsula. The next day, the telephone hotline was connected for the first time since February 2016, so Moon and Kim could talk directly.

Kim announced North Korea would stop nuclear and missile tests. Kim said: "We no longer need any nuclear test or test launches of intermediate and intercontinental range ballistic missiles, and because of this the northern nuclear test site has finished its mission." However, no mention was made of its stored nuclear materials and equipment.

Kim and Moon Jae-in meet in the border town of Panmunjom in the Demilitarized Zone (DMZ) that has divided the two Koreas since the Korean War in 1953. The two leaders vowed to work towards a nuclear-free Korea and pledged an end to war. It was the first time a North Korean leader had set foot across the border since the 1950s and paves the diplomatic way for a Trump-Kim meeting in May or June.

South Korea announces its propaganda loudspeakers are to be switched off for good. They had been silenced temporarily ahead of the inter-Korean summit, which prompted the North to halt its broadcasts, too. Pyongyang also said it would adjust its time zone to that of the South as a symbolic gesture. North Korea has been half an hour behind the South since 2015.

After North Korea slammed US Vice President Mike Pence for comparing North Korea and Libya, Donald Trump abruptly canceled the summit. Trump said the move was due to "tremendous anger and open hostility" displayed by Pyongyang.

A day after scrapping the summit, Trump suggested he was still open to meeting Kim. US and North Korean officials met during the following week and on June 1, Trump met one of Kim's closest aides, Kim Yong Chol, in the White House. Shortly thereafter, Trump said the summit would indeed take place on June 12 in Singapore. "I think you're going to have a very positive result in the end," he said.

Trump and Kim met in Singapore as planned. They smiled, shook hands and praised how far they had come in overcoming their previous animosity. The summit ended with both leaders signing a short joint declaration that committed Pyongyang to denuclearize and the US to providing unspecified "security guarantees" to the North. Trump also said he would invite Kim to the White House.

In early June 2017, North Korea test-launched an intercontinental ballistic missile (ICBM) for the first time. Testing an ICBM marked a major military achievement for Pyongyang and a serious escalation of tensions with the United States and its allies in the region, particularly South Korea and Japan.

At the time, defense experts said the ICBM could reach as far as the US states of Alaska and Hawaii. However, it was unclear if North Korea can field an ICBM capable of carrying a nuclear warhead on its cone that could survive reentry into the Earth's atmosphere. North Korean state media claimed the ICBM was capable of carrying a "large, heavy nuclear warhead" to any part of the United States.

The ICBM is believed to be a step forward in the North's nuclear program. Despite pressure from the international community, Pyongyang has made no secret of its nuclear ambitions. Alongside its ritual ballistic missile tests, North Korea has conducted nuclear tests on at least six occasions, including one in September 2017.

Responding to the first ICBM test with a show of force, the US and South Korean troops on conducted "deep strike" precision missile drills using Army Tactical Missile System (ATACMS) and the Republic of Korea's Hyunmoo Missile II. In April, the US sent its Carl Vinson aircraft carrier towards the Korean Peninsula, saying it was taking prudent measures against the North.

Ignoring international condemnation, Pyongyang test-launched another rocket on July 28, 2017, just weeks after its first ICBM test. In both of the tests, North Korea used Hwasong-14 missile, but the second one reached a higher altitude and traveled a larger distance than the first one, according to the state media.

Pyongyang conducted its third test November 29, using a newly developed Hwasong-15 missile. US, Japanese and South Korean officials said it rose to about 4,500 km (2,800 miles) and flew 960 kilometers (600 miles) over about 50 minutes before landing in Japan's exclusive economic zone off the country's coast.

Apart from a developing missile and nuclear program, North Korea has a powerful army with 700,000 active troops and another 4.5 million in the reserves. It can call upon almost a quarter of its population to serve in the army at any given time. The North's bloated army is believed to outnumber its southern neighbor's by two-to-one.

According to the 2017 Global Firepower Index, the North has, as part of a far-reaching arsenal, 458 fighter aircraft, 5,025 combat tanks, 76 submarines, and 5,200,000 total military personnel. The picture above from 2013 shows leader Kim Jong Un ordering strategic rocket forces to be on standby to strike US and South Korean targets at any time.

Alongside the United States, Pyongyang views its neighbors South Korea and Japan as its two other main enemies. North Korea has used US military exercises in the region as means of galvanizing its people, claiming that the exercises are dress rehearsals for an impending invasion.

Every year, hundreds of thousands of soldiers and citizens roll through the streets of the capital Pyongyang to take part in the North's military parades. Preparations for the rallies often begin months in advance, and the parades usually mark important anniversaries linked with the Communist Party or Kim Jong Un's family.