america

U.S. President Barack Obama waves as he arrives to give a speech in front of the Brandenburg Gate at Pariser Platz in Berlin.

Michael Kappeler/Reuters

Barack Obama, US president, waves as he arrives to give a speech in front of the Brandenburg Gate at Pariser Platz in Berlin on Wednesday Read more

A Marine closes a door to Marine One with US President Barack Obama on the South Lawn of the White House on May 28, 2013 in Washington. Obama is traveling to the New Jersey shore to survey rebuilding efforts in areas effected by last year's hurricane Sandy.     AFP PHOTO/Brendan SMIALOWSKIBRENDAN SMIALOWSKI/AFP/Getty Images

Brendan Smialowski/AFP

A Marine on Tuesday closes the door to Marine One, carrying President Barack Obama, on the south lawn of the White House, Washington. Mr Obama is travelling to the New Jersey shore to survey rebuilding efforts in areas affected by last year’s Hurricane SandyRead more

Michelle Obama Visits Local Washington DC School...WASHINGTON, DC - MAY 24:  U.S. first lady Michelle Obama dances with pre-kindergarten students while she visits the Savoy School May 24, 2013 in Washington, DC. The Savoy School, once one of the lowest performing schools in the District of Columbia, has shown significant signs of improvement since being designated as one of eight schools selected last year for the Turnaround Arts Initiative by the President's Committee on the Arts and the Humanities.  (Photo by Win McNamee/Getty Images)

Win McName/Getty

US First Lady Michelle Obama dances with pre-kindergarten students while she visits the Savoy School on Friday in Washington, DC. The school, once one of the lowest performing in the District of Columbia, has shown significant signs of improvement since being designated as one of eight schools selected last year for the Turnaround Arts Initiative by the President’s Committee on the Arts and the Humanities. Read more

S First Lady Michelle Obama (C) is surr...US First Lady Michelle Obama (C) is surrounded by 6th graders from Fairfax, Viginia's Willow Springs Elementary School during a surprise visit to the Decatur House in Washington, DC, May 22, 2013. The Decatur House is a National Trust for Historic Preservation Site which received a $ 1 million grant from American Express to preserve the Slave Quarters structure and fund educational programming.     AFP PHOTO/JIM  WATSONJIM WATSON/AFP/Getty Images

Jim Watson/AFP

Michelle Obama, the US first lady, meets sixth graders from Willow Springs elementary school in Fairfax, Virginia, during a surprise visit to Decatur House, a historic building in Washington, on Wednesday. Decatur House is a National Trust for Historic Preservation site, which received a $1m grant from American Express to preserve its slave quarters and fund educational programming Read more

Solar Impulse, piloted by AndrĂˆ Borschberg, takes flight during the second leg of the 2013 Across America mission, at dawn, Wednesday, May 22, 2013, from Sky Harbor International Airport in Phoenix. The solar powered aircraft is scheduled to land at Dallas/Fort Worth International Airport on Thursday May 23. The plane's creators, Bertrand Piccard and Borschberg, said the trip is the first attempt by a solar airplane capable of flying day and night without fuel to fly across America. (AP Photo/Matt York)

Matt York/AP

Solar Impulse, piloted by AndrĂ© Borschberg, takes flight during the second leg of the 2013 Across America mission at dawn on Wednesday from Sky Harbor International Airport in Phoenix, Arizona. Read more

Barack Obama, David Cameron...President Barack Obama and British Prime Minister David Cameron walk off the stage after their joint news conference,  Monday, May 13, 2013, in the East Room of the White House in Washington, where they talked about various topics including Syria's civil war. (AP Photo/Jacquelyn Martin)

Jacquelyn Martin/AP

US President Barack Obama and British Prime Minister David Cameron walk off the stage after their joint news conference on Monday in the East Room of the White House in Washington, where they talked about various topics including Syria’s civil war. Read more

Ariel Castro, Pedro Castro and Onil Castro appear in court in Cleveland,...Ariel Castro (R), Pedro Castro (C) and Onil Castro appear in court in Cleveland, Ohio, May 9, 2013. Ariel Castro, 52, a veteran school bus driver fired from his job last fall, was formally charged with kidnapping and raping the three women, who were rescued from his house on May 6 evening shortly before his arrest.  REUTERS/John Gress (UNITED STATES - Tags: CRIME LAW TPX IMAGES OF THE DAY)

John Gress/Reuters

Ariel Castro (R), Pedro Castro (C) and Onil Castro appear in court in Cleveland, Ohio on Thursday. Ariel Castro, 52, a veteran school bus driver was fired from his job last autumn, was formally charged with kidnapping and raping the three women, who were rescued from his house on Monday. Read more

The Dalai Lama attends the Anwar Sadat Lecture for Peace at the University of Maryland...Tibetan spiritual leader the Dalai Lama adjusts his University of Maryland visor while attending the Anwar Sadat Lejcture for Peace at the University of Maryland in College Park, Maryland May 7, 2013.    REUTERS/Gary Cameron  (UNITED STATES - Tags: RELIGION POLITICS)

Gary Cameron/Reuters

Tibetan spiritual leader the Dalai Lama adjusts his University of Maryland visor while attending the Anwar Sadat Lecture for Peace at the University of Maryland in College Park, Maryland on Tuesday.

U.S. President Obama delivers speech in Mexico City...U.S. President Barack Obama delivers a speech at the Anthropology Museum during his visit to Mexico City May 3, 2013.   REUTERS/Kevin Lamarque   (MEXICO - Tags: POLITICS)

Kevin Lamarque/Reuters

US President Barack Obama delivers a speech at the Anthropology Museum during his visit to Mexico City on Friday. Read more

US President Barack Obama and First Lady

Jewel Samad/AFP

President Barack Obama heads to Boston to mourn victims of the Boston Marathon attacks. No arrests have been made in connection with Monday’s twin bombings near the finish line of the race, which sent metal fragments and nails into a crowd of runners and spectators, killing three people and wounding 180.