Since 2011, Kim Jong Un has fired more than 90 missiles and conducted four nuclear weapons tests.

While the details of the unprecedented summit between President Donald Trump and Kim Jong Un begin to take shape, experts are reminding everyone that North Korea spent most of 2017 perfecting its missile arsenal. One expert even voiced his skepticism by comparing the relationship between the U.S. and North Korea to a recurring scene of frustration in "Peanuts" cartoons. "Historically, every time Charlie Brown runs for the football, Lucy pulls it away," Thomas Karako, director of the Missile Defense Project at the Center for Strategic and International Studies, told CNBC. "It would be a remarkable thing if Lucy didn't pull the football out from Charlie Brown this time, but it's one of those things where I'll believe it when I see it."

North Korean leader Kim Jong Un inspects the intermediate-range ballistic missile Pukguksong-2's launch test in this undated photo released by North Korea's Korean Central News Agency, May 22, 2017. KCNA | Reuters

North Korea is Lucy in this case. Under third-generation North Korean leader Kim, the reclusive state has conducted its most powerful nuclear test, launched its first-ever intercontinental ballistic missile and threatened to send missiles into the waters near the U.S. territory of Guam. What's more, the acceleration and frequency of testing show not only Kim's nuclear ambitions but also that the nation has developed an arsenal. (Click on the graphic to expand.)

Since 2011, Kim has fired more than 90 missiles and conducted four nuclear weapons tests, which is more than what his father, Kim Jong Il, and grandfather, Kim Il Sung, launched over a period of 27 years. The North's arsenal includes short- and medium-range ballistic missiles, intercontinental ballistic missiles and cruise missiles. The Hwasong-15 intercontinental ballistic missile is the most powerful rocket the North has tested to date. The missile, also known as KN-22 by the U.S., is believed to have a range capable of hitting the entire continental United States, according to estimates from the Missile Defense Project. In 2017 alone, Kim launched 24 missiles and carried out North Korea's largest nuclear test.

As it stands, North Korea remains the only nation to test nuclear weapons in this century. On Sept. 3, the rogue regime carried out its sixth and most powerful nuclear test, saying it detonated an advanced hydrogen bomb designed for a long-range missile. The bomb is estimated to have had an explosive yield of 120 kilotons, which equates to a blast created from 265 million pounds worth of TNT, according to Norsar, a Norwegian geoscience research foundation.