The Empire State Building towers over the Manhattan skyline as tourists gather on the observation deck of Rockefeller Center on February 13, 2012 in New York City. The owner of the Empire State Building, Malkin Holdings, plans to raise up to $1 billion in an initial public offering on the 102 story Manhattan landmark. (Photo by John Moore/Getty Images)

Iraqi security forces take part in training, as they prepare to fight against militants of the Islamic State, at a training camp on the outskirts of Mosul January 10, 2015. (Photo by Azad Lashkari/Reuters)

A reveler waves a gay pride flag in front of the historic gay bar The Stonewall after the passing of a bill legalizing gay marriage in New York State on June 24, 2011 in New York City. New York State now joins Connecticut, Massachusetts, New Hampshire, Vermont, Iowa and Washington, D.C. in legally recognizing gay marriage. (Photo by Spencer Platt/Getty Images)

Iraqi troops fire artillery towards Islamic State (IS) group jihadists' positions in west Mosul on March 11, 2017 during the ongoing battle to retake the city from the group. (Photo by Aris Messinis/AFP Photo)

Iraqi forces launch a rocket in Mosul's eastern Al-Intisar neighbourhood on December 30, 2016, during an ongoing military operation against Islamic State (IS) group jihadists. Iraqi forces advanced on December 29 after declaring a new phase in their offensive on eastern Mosul, stepping up efforts to reclaim the Islamic State group's last major stronghold in the country. (Photo by Ahmad Al-Rubaye/AFP Photo)

An Iraqi special forces Counter Terrorism Service (CTS) member screams during a battle against Islamic State group jihadists (IS) in Mosul's al-Rifaq neighbourhood on January 8, 2017, as an ongoing military operation against the militants continues. Elite Iraqi forces battling the Islamic State group in eastern Mosul reached the Tigris River that splits the city in two for the first time, a spokesman said. (Photo by Dimitar Dilkoff/AFP Photo)

A woman from a group called “Las Patronas” (The bosses), a charitable organization that feeds Central American immigrants who travel atop a freight train known as “La Bestia”, passes food and water to immigrants on their way to the border with the United States, at Amatlan de los Reyes, in Veracruz state, Mexico October 22, 2016. (Photo by Daniel Becerril/Reuters)

A rag-and-bone woman stands next to carriages of a coal train outside a coal mine of the state-owned Longmay Group on the outskirts of Jixi, in Heilongjiang province, China, October 22, 2015. (Photo by Jason Lee/Reuters)