A woman wearing leggings with the colours of the US flag walks along a street of Havana on February 18, 2015. President Barack Obama announced Thursday he will make a landmark visit to Cuba on March 21-22, pledging to address human rights as America pursues a historic thaw with its former Cold War foe. (Photo by Yamil Lage/AFP Photo)

This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)

Supporters and opponents of Russian opposition activist and anti-corruption crusader Alexei Navalny clash during unsanctioned protest in Manezhnaya Square in Moscow, Russia, Tuesday, December 30, 2014. The unsanctioned protest came hours after Alexei Navalny was found guilty of fraud and given a suspended sentence. Navalny, who has been under house arrest since February, is accused of breaking the terms of his house arrest to attend the rally and was detained by police as he approached the site of the protest. (Photo by Ivan Sekretarev/AP Photo)

A Hindu devotee girl stands after getting her tongue pierced with a metal rod during the Thaipusam festival in Kuala Lumpur, Malaysia, Tuesday, February 3, 2015. Thaipusam, which is celebrated in honor of Hindu god Lord Murugan, is an annual procession by Hindu devotees seeking blessings, fulfilling vows and offering thanks. (Photo by Joshua Paul/AP Photo)

A Colombian flower grower selects a rose for a bouquet ahead of Valentine's Day in Subachoque, February 2, 2015. Colombia is the world's second-largest flower exporter behind the Netherlands. The Andean country exports around 500 million flowers to the U.S. for Valentine's Day, according to the Colombia Flower Growers Association. (Photo by John Vizcaino/Reuters)

David Pena poses for a photograph with his Lada 2101 built in 1979 on a street in Havana February 9, 2015. Getting parts from the United States is cheaper than in Cuba, where state-run stores sell them at four times the cost, said Pena, a mechanic and president of the Russian Car Club in Havana who drives a souped-up, sporty red 1972 Lada 2101 that he fixed himself. His own Lada has a Fiat engine and an extra Alfa Romeo carburetor. (Photo by Enrique De La Osa/Reuters)

Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

Hindu holy man, or sadhu, applies paint to his forehead at his ashram on the premises of Pashupatinath Temple in Kathmandu February 15, 2015. Hindu holy men from Nepal and India come to this temple to take part in the Maha Shivaratri festival. Celebrated by Hindu devotees all over the world, Shivaratri is dedicated to Lord Shiva, and holy men mark the occasion by praying, smoking marijuana or smearing their bodies with ashes. (Photo by Navesh Chitrakar/Reuters)