European Union

A US army officer escorts US President Barack Obama (2nd-L), Belgium's King Philippe (2nd-R) and Belgian Prime Minister Elio Di Rupo (R) as they visit the WWI Flanders Field Cemetery in Waregem on Wednesday. The cemetery is the final resting place for 368 Americans, most of whom were killed during World War I. Obama will pay his first visit ever to the EU headquarters in Brussels, cementing US-EU opposition to the takeover of Crimea after hitting out at Russian expansionism as a "sign of weakness".

Belga/AFP

A US army officer escorts US President Barack Obama (2nd-L), Belgium’s King Philippe (2nd-R) and Belgian Prime Minister Elio Di Rupo (R) as they visit the WWI Flanders Field Cemetery in Waregem on Wednesday. The cemetery is the final resting place for 368 Americans, most of whom were killed during World War I. Obama will pay his first visit ever to the EU headquarters in Brussels, cementing US-EU opposition to the takeover of Crimea after hitting out at Russian expansionism as a “sign of weakness”.

Pilgrims cheer Pope Francis as he greets the crowd during his general audience at St Peter's square on March 26, 2014 at the Vatican.

Vincenzo Pinto/AFP

Pilgrims cheer Pope Francis as he greets the crowd during his general audience at St Peter’s square on Wednesday at the Vatican.

In this photo taken on Thursday Feb. 20, 2014, a motorcyclist passes the work 'Access Control' by Greek street artist iNO, on central Pireos Street in Athens. Greece has attracted international street artists to its capital, due to the availability of commissioned work and relatively lax anti-graffiti law.

Dimitri Messinis/AP

A motorcyclist passes the work ‘Access Control’ by Greek street artist iNO, on central Pireos Street in Athens. Greece has attracted international street artists to its capital, due to the availability of commissioned work and relatively lax anti-graffiti law. Read more

A man adjusts a spotlight above the stage before world leaders' family picture during the Nuclear Security Summit in The Hague...A man adjusts a spotlight above the stage before world leaders' family picture during the Nuclear Security Summit in The Hague March 25, 2014.  REUTERS/Robin Van Lonkhuijsen/Pool (NETHERLANDS  - Tags: POLITICS)

Robin Van Lonkhuijsen/Reuters

The stage is set before world leaders have their family picture taken before the Nuclear Security Summit in The Hague, The NetherlandsRead more

***BESTPIX*** Syrian opposition leads attack on regime-controlled town...HATAY, TURKEY - MARCH 24: Syrian opposition forces seize Latakia's Kasab town, on March 24, 2014, in Hatay, Turkey. After the regime forces have lost the only controlled area at the Turkish border gate, they have attacked to seize the town of Kasab, Latakia for 4 days. (Photo by Emin Sansar/Anadolu Agency/Getty Images) ***BESTPIX***

Emin Sansar/Anadolu Agency/Getty

Syrian opposition forces seize Latakia’s Kasab town, on Monday, in Hatay, Turkey. After the regime forces have lost the only controlled area at the Turkish border gate, they have attacked to seize the town of Kasab, Latakia for 4 days Read more

Protestors with a radioactive sign painted on their faces pose during a demonstration on the first day of the two-day Nuclear Security Summit) in The Hague, Netherlands.

Patrick Post/AP

Protestors with a radioactive sign painted on their faces pose during a demonstration on the first day of the two-day Nuclear Security Summit in The Hague, Netherlands.

An elephant stretches its trunk towards the photographer's lens during a photo call at the Circus Charles Knie in Hanover, central Germany, on March 24, 2014. The circus with 110 animals and 100 employees gives guest performances in Hanover until April 6, 2014.

Julien Stratenschulte/AFP

An elephant stretches its trunk towards the photographer’s lens during a photo call at the Circus Charles Knie in Hanover, central Germany, on Monday. The circus with 110 animals and 100 employees gives guest performances in Hanover until April 6, 2014.

World Leaders Gather For Nuclear Security Summit 2014...AMSTERDAM, NETHERLANDS - MARCH 24: US President Barack Obama (L) and Prime Minister of the Netherlands Mark Rutte (C) visit the Rijksmuseum ahead of the 2014 Nuclear Security Summit on March 24, 2014 in Amsterdam, Netherlands. The Nuclear Security Summit, held March 24-25, will be attended by world leaders and is aimed at preventing nuclear terrorism.

Jerry Lampen/Getty

Barack Obama, US president (left), and Mark Rutte, Netherlands prime minister (centre), meet in front of Rembrandt’s ‘The Night Watch’ in the Rijksmuseum in Amsterdam before the start of the 2014 Nuclear Security Summit. The summit, held March 24-25, will be attended by world leaders and is aimed at preventing nuclear terrorism.

Chinese artist  Zhang Xun  poses in a installation created in a special 3D-technique during a press preview in the exhibition 'You Are The Art' ('Du bist die Kunst') by a Chinese artist group at Augustusburg castle in Augustusburg, Germany, Friday, March 21, 2014. Visitors are invited to take pictures of themselves interacting with the art and to share the results on social networks. The exhibition includes 23 paintings and lasts from  March 22, 2014  to June 22, 2014.

Jens Meyer/AP

Chinese artist Zhang Xun poses in a installation created in a special 3D-technique during a press preview in the exhibition ‘You Are The Art’ (‘Du bist die Kunst’) by a Chinese artist group at Augustusburg castle in Augustusburg, Germany. Visitors are invited to take pictures of themselves interacting with the art and to share the results on social networks. The exhibition includes 23 paintings and lasts from Saturday until June 22.

Germany's Chancellor Angela Merkel looks through her window as she arrives at a European Union leaders summit in Brussels March 21, 2014. EU leaders added 12 people to a list of those subject to travel bans and asset freezes for their part in Russia's seizure of Crimea on Thursday and begin preparations for economic sanctions if Russia expands its footprint in Ukraine.

Francois Lenoir /Reuters

Germany’s Chancellor Angela Merkel looks through her car window as she arrives at the EU leaders summit in Brussels