UNITED STATES - JUNE 4: House Minority Whip Steny Hoyer, D-Md., speaks during a press conference with House Democrats on the Export-Import Bank in the Capitol on Thursday, June 4, 2015. (Photo By Bill Clark/CQ Roll Call)
This photo taken on May 6, 2016 and released on May 7 by North Korea's official Korean Central News Agency (KCNA) shows North Korean leader Kim Jong-Un reporting works of North Korean Workers Party Central Committee during the 7th Workers Party Congress at the 'April 25 Palace' in Pyongyang. / AFP / KCNA VIA KNS / STR (Photo credit should read STR/AFP/Getty Images)
U.S. Secretary of State Hillary Clinton checks her PDA upon departure in a military C-17 plane from Malta bound for Tripoli, on October 18, 2011. AFP PHOTO/KEVIN LAMARQUE/POOL (Photo credit should read KEVIN LAMARQUE/AFP/Getty Images)
This undated picture released from North Korea's official Korean Central News Agency (KCNA) on June 23, 2016 shows North Korean leader Kim Jong-Un (C) inspecting a test of the surface-to-surface medium long-range strategic ballistic missile Hwasong-10 at an undisclosed location in North Korea.
The Musudan -- also known as the Hwasong-10 -- has a theoretical range of anywhere between 2,500 and 4,000 kilometres (1,550 to 2,500 miles). / AFP / KCNA VIA KNS / KCNA / South Korea OUT / REPUBLIC OF KOREA OUT ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/KCNA VIA KNS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS
THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE. THIS PHOTO IS DISTRIBUTED EXACTLY AS RECEIVED BY AFP. / (Photo credit should read KCNA/AFP/Getty Images)
State Department Spokesman John Kirby speaks during the daily briefing at the State Department on January 6, 2015 in Washington, DC. Even as world powers work to implement the Iran nuclear deal, North Korea's apparent detonation of a new bomb marks a stark setback for global anti-proliferation efforts. Kirby's message to Pyongyang was clear -- "we have consistently made clear that we will not accept it as a nuclear state" -- but not new. AFP PHOTO/MANDEL NGAN / AFP / MANDEL NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)
WASHINGTON, USA - JUNE 28: Brett McGurk, Special Presidential Envoy for the Global Coalition to Counter ISIL, answers questions from Senators during a Senate Foreign Relations Committee hearing on the global efforts to defeat ISIS at the U.S. Capitol in Washington, USA on June 28, 2016. (Photo by Samuel Corum/Anadolu Agency/Getty Images)
BERLIN, GERMANY - JULY 10: Visitors chat in the public information representation of the European Commission near a sign promoting the TTIP free trade agreement between the U.S. and the European Union on July 10, 2015 in Berlin, Germany. TTIP, which is still being negotiated by the two sides, has come under a hail of popular criticism in Germany. (Photo by Sean Gallup/Getty Images)
PHILADELPHIA, PA - JULY 09: Former NBA player Shaquille O' Neal at the Reebok Classic Breakout Classic Rap Roundtable at Philadelphia University on July 9, 2014 in Philadelphia, Pennsylvania. (Photo by Lisa Lake/Getty Images for Reebok)
Robert Kagan is an American historian and foreign policy commentator. He is a senior fellow at the Brookings Institution and an adjunct professor of history at Georgetown University, and was listed by Foreign Policy and Prospect as one of the world's "Top 100 Public Intellectuals". (Photo by Brooks Kraft LLC/Corbis via Getty Images)
COLUMBUS, OH - NOVEMBER 23: Republican presidential candidate Donald Trump addresses supporters during a campaign rally at the Greater Columbus Convention Center on November 23, 2015 in Columbus, Ohio. Trump spoke about immigration and Obamacare, among other topics, to around 14,000 supporters at the event. (Photo by Ty Wright/Getty Images)
Rebel fighters walk in front of damaged buildings in Karm al-Jabal neighbourhood of Aleppo on August 26, 2014. The United States has begun reconnaissance flights over Syria and is sharing intelligence about jihadist deployments with Damascus through Iraqi and Russian channels, sources told AFP. AFP PHOTO/AMC/ZEIN AL-RIFAI (Photo credit should read ZEIN AL-RIFAI/AFP/Getty Images)
Ben Rhodes, Deputy National Security Advisor to US President Barack Obama, speaks about the President's upcoming trip to Cuba during a daily press briefing at the White House February 18, 2016 in Washington, DC.
Cuba's government Thursday hailed Obama's planned visit to the island in March as a new step towards mending relations between longtime foes Havana and Washington. / AFP / Brendan Smialowski (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images)
WASHINGTON - JUNE 5: The U.S. Capitol is shown June 5, 2003 in Washington, DC. Both houses of the U.S. Congress, the U.S. Senate and the U.S. House of Representatives meet in the Capitol. (Photo by Stefan Zaklin/Getty Images)