A Chinese paramilitary policeman stands guard in front of the plane US Secretary of State Rex Tillerson boarded for his departure at the airport in Beijing on March 19, 2017. Tillerson earlier in the day met with China's President Xi Jinping on March 19 just hours after a North Korean rocket engine test added new pressure on the big powers to address the threat from Pyongyang. / AFP PHOTO / POOL / THOMAS PETER (Photo credit should read THOMAS PETER/AFP/Getty Images)
