Visitors watch a news broadcast showing file footage of a North Korean missile test at the ferry terminal of South Korea's eastern island of Ulleungdo, in the East Sea, also known as the Sea of Japan, on Thursday. Anthony Wallace/AFP via Getty Images hide caption
People watch a television screen showing a news broadcast with file footage of a North Korean missile test, at a railway station in Seoul on Wednesday, after North Korea fired an "unidentified projectile." Jung Yeon-je/AFP via Getty Images hide caption
In this photo provided by the North Korean government, North Korean leader Kim Jong Un, center, attends a meeting of the Central Committee of the ruling Workers' Party in Pyongyang, North Korea. AP File Photo hide caption
Experts worry that North Korea may be about to test an advanced solid-fuel missile. Wong Maye-E/AP hide caption
North Korean leader Kim Jong Un and South Korean President Moon Jae-in during the Inter-Korean Summit in April of last year in Panmunjom, South Korea. NurPhoto via Getty Images hide caption
South Koreans in Seoul on Wednesday watch a news report about a missile launch. Chung Sung-Jun/Getty Images hide caption
Pedestrians walk past a screen in Tokyo reporting about North Korea's test firing of a rocket system off the coast of North Korea on Wednesday. Kazuhiro Nogi/AFP/Getty Images hide caption
South Koreans in Seoul watch a file image of North Korean leader Kim Jong Un observing a missile launch after Pyongyang's latest test was announced on Wednesday. Chung Sung-Jun/Getty Images hide caption
A man at a railway station in Seoul watches a television showing file footage of a North Korean missile launch on Thursday. Earlier, North Korea had fired two short-range missiles into the sea. Jung Yeon-je/AFP/Getty Images hide caption
North Korea on Thursday fired projectiles that are believed to be missiles from the country's western area, South Korea's military says. The same day in Seoul, people watch a TV showing footage of a previous missile launch by North Korea. Ahn Young-joon/AP hide caption
In this Dec. 12, 2012, file photo released by Korean Central News Agency, North Korea's Unha-3 rocket lifts off from the Sohae launch pad in Tongchang-ri, North Korea. In 2018, North Korea's government said it would destroy the facility. KCNA via AP hide caption
President Trump shakes hands with Japanese Prime Minister Shinzo Abe during a joint press conference in the Rose Garden of the White House on Thursday. Nicholas Kamm/AFP/Getty Images hide caption
Participants take refuge underground during an evacuation drill simulating a North Korea ballistic missile attack Monday in Tokyo. Shizuo Kambayashi/AP hide caption
South Korean Unification Minister Cho Myung-gyun (left) shakes hands with North Korean chief delegate Ri Son Gwon after their meeting Tuesday at the village of Panmunjom in the Demilitarized Zone dividing the two countries. AFP/Getty Images hide caption
A U.S. Air Force B-1B "Lancer" bomber flying with F-35B fighter jets and South Korean Air Force F-15K fighter jets during a training at the Pilsung Firing Range in South Korea in September. Handout/South Korean Defense Ministry vi hide caption
A man at a railway station in Seoul watches as North Korean leader Kim Jong Un delivering a statement in Pyongyang. Jung Yeon-je/AFP/Getty Images hide caption
Elementary school students in Iwamizawa, a town in Japan's Hokkaido prefecture, take part in a missile drill. Elise Hu/NPR hide caption
A South Korean soldier at the Seoul Train Station watches footage of North Korea's missile launch on Saturday. Lee Jin-man/AP hide caption
The Homeland Security website Ready.gov warns that following a nuclear blast, you should wash your hair with shampoo but not use conditioner, because conditioner can bind radioactive material to your hair. Smith Collection/Getty Images hide caption
South Koreans watch television coverage of the July 4 launch of a Hwasong-14 intercontinental ballistic missile, ICBM, in North Korea. Lee Jin-man/AP hide caption
President Trump talks about North Korea during a briefing on the opioid crisis Tuesday at the Trump National Golf Club in Bedminster, N.J. Evan Vucci/AP hide caption
A rocket designed to intercept an intercontinental ballistic missile is launched from Vandenberg Air Force Base in California on Tuesday. The Pentagon says it shot down a mock warhead over the Pacific in a success for the U.S. missile defense program. Matt Hartman/AP hide caption
The news of North Korea's missile firing is broadcast at Seoul Train Station in South Korea on Monday. Lee Jin-man/AP hide caption
North Korean leader Kim Jong Un is shown on a TV at the Seoul Railway Station in South Korea on Sunday, when North Korea test-launched a "medium long-range" missile that landed in the waters between Japan and the Korean Peninsula. Ahn Young-joon/AP hide caption