Afghan President, Ashraf Ghani (R) shakes hands with US Secretary of Defense, Ash Carter during a joint press conference at the Presidential Palace in Kabul on July 12, 2016. US Defence Secretary Ashton Carter reiterated Washington's support for "courageous" Afghan security forces July 12, days after the United States and NATO pledged to keep thousands of troops in the troubled country. / AFP PHOTO / SHAH MARAISHAH MARAI/AFP/Getty Images

A demonstrator with "We The People For Sensible Gun Laws" protests outside the White House July 11, 2016, in Washington, DC. The group is calling on Congress to "recognize the nexus between domestic abuse and gun violence," "require universal background checks," "require gun safety training," "reinstate the assault weapons ban," "ban high capacity ammunition magazines," "recognize this is a public health emergency," and "provide research funds into causes and solutions to gun violence." / AFP PHOTO / JIM WATSONJIM WATSON/AFP/Getty Images

Demonstrators with "We The People For Sensible Gun Laws" protest outside the White House July 11, 2016, in Washington, DC. The group is calling on Congress to "recognize the nexus between domestic abuse and gun violence," "require universal background checks," "require gun safety training," "reinstate the assault weapons ban," "ban high capacity ammunition magazines," "recognize this is a public health emergency," and "provide research funds into causes and solutions to gun violence." / AFP PHOTO / JIM WATSONJIM WATSON/AFP/Getty Images

A demonstrator with "We The People For Sensible Gun Laws" holds a placard as she and others protest outside the White House July 11, 2016, in Washington, DC. The group is calling on Congress to "recognize the nexus between domestic abuse and gun violence," "require universal background checks," "require gun safety training," "reinstate the assault weapons ban," "ban high capacity ammunition magazines," "recognize this is a public health emergency," and "provide research funds into causes and solutions to gun violence." / AFP PHOTO / JIM WATSONJIM WATSON/AFP/Getty Images

Demonstrators with "We The People For Sensible Gun Laws," read off the names of victims of gun violence in the DC Metro area as they protest outside the White House July 11, 2016, in Washington, DC. The group is calling on Congress to "recognize the nexus between domestic abuse and gun violence," "require universal background checks," "require gun safety training," "reinstate the assault weapons ban," "ban high capacity ammunition magazines," "recognize this is a public health emergency," and "provide research funds into causes and solutions to gun violence." / AFP PHOTO / JIM WATSONJIM WATSON/AFP/Getty Images

WASHINGTON, DC - JULY 10: U.S. President Barack Obama returns to the White House after a trip to Europe where he attended the 2016 NATO Summit in Warsaw Poland, and met with King Don Felipe VI of Spain July 10, 2016 in Madrid, Spain. (Photo by Aude Guerrucci-Pool/Getty Images)

WASHINGTON, DC - JULY 10: U.S. President Barack Obama returns to the White House after a trip to Europe where he attended the 2016 NATO Summit in Warsaw Poland, and met with King Don Felipe VI of Spain July 10, 2016 in Madrid, Spain. (Photo by Aude Guerrucci-Pool/Getty Images)

WASHINGTON, DC - JULY 10: U.S. President Barack Obama returns to the White House after a trip to Europe where he attended the 2016 NATO Summit in Warsaw Poland, and met with King Don Felipe VI of Spain July 10, 2016 in Madrid, Spain. (Photo by Aude Guerrucci-Pool/Getty Images)