US President Barack Obama, First Lady Michelle Obama and their daughters Malia and Sasha(L) walk to St John's Church across from the White House in Washington, DC, on July 17, 2011 to attend a Sunday prayer service . AFP Photo/Jewel Samad

US President Barack Obama holds his daughter Sasha as they walk back to the White House from the St John's Church in Washington, DC, on July 17, 2011 after attending a Sunday prayer service . AFP Photo/Jewel Samad

US President Barack Obama answers a question by a reporter if he is going to watch FIFA women's soccer world cup today as he and his daughter Sasha walk back to the White House from the St John's Church in Washington, DC, on July 17, 2011 after attending a Sunday prayer service. Obama said he is "absolutely" going to watch the FIFA women's soccer world cup being played between US and Japan in Germany today. AFP Photo/Jewel Samad

PHOTO: JAN KUCHARZYK/EAST NEWS WARSZAWA 28/05/2011 WIZYTA PREZYDENTA STANOW ZJEDNOCZONYCH AMERYKI POLNOCNEJ BARACKA OBAMY W WARSZAWIE. OFICJALNE POWITANIE PRZED PALACEM PREZYDENCKIM. N/Z: BARACK OBAMA I BRONISLAW KOMOROWSKI

US President Barack Obama chats with Japanese Prime Minister Naoto Kan (not pictured) after a meeting at the Royal Barriere hotel on the sideline of the G8 summit in Deauville on May 26, 2011. Obama on Thursday told Japan's Prime Minister Naoto Kan that the United States would stand with its key Asian ally for as long as it took to recover from its disaster. AFP PHOTO / JEWEL SAMAD

US President Barack Obama chats with Japanese Prime Minister Naoto Kan (not pictured) after a meeting at the Royal Barriere hotel on the sideline of the G8 summit in Deauville on May 26, 2011. Obama on Thursday told Japan's Prime Minister Naoto Kan that the United States would stand with its key Asian ally for as long as it took to recover from its disaster. AFP PHOTO / JEWEL SAMAD

US President Barack Obama plays table tennis with British Prime Minister David Cameron (unseen) against students of the Globe Academy school in London on May 24, 2011. Obama basked on May 24, 2011 in the lavish royal pageantry of a state visit to Britain, given an extra dash of glamour by a brief encounter with Prince William and his new bride Catherine. AFP PHOTO/ JEWEL SAMAD

US President Barack Obama speaks after a meeting with Irish Prime Minister (Taoiseach) Enda Kenny (unseen) at the Farmleigh, in Dublin on May 23, 2011. Obama landed in Ireland on May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ JEWEL SAMAD

US President Barack Obama (L) poses for pictures with an Irish hurling stick following a meeting with Irish Prime Minister Enda Kenny at Farmleigh in Dublin, Ireland, on May 23, 2011. Obama landed in Ireland on Monday for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO / MAXWELLS/POOL

CROPPED VERSION US President Barack Obama sips a Guinness at a pub as they visit Moneygall village in rural County Offaly, Ireland, where his great-great-great grandfather Falmouth Kearney hailed from, on May 23, 2011. Obama landed in Ireland on May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ JEWEL SAMAD

US President Barack Obama waves to fans after delivering a speech to crowds of people during a public rally at College Green in Dublin, Ireland, on May 23, 2011. US President Barack Obama landed in Ireland May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ CARL DE SOUZA

US President Barack Obama waves to fans during a public rally at College Green in Dublin, Ireland, on May 23, 2011. US President Barack Obama landed in Ireland May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ CARL DE SOUZA

US President Barack Obama waves to fans during a public rally at College Green in Dublin, Ireland, on May 23, 2011. US President Barack Obama landed in Ireland May 23, 2011 for a visit celebrating his ancestral roots, kicking off a four-nation European tour. AFP PHOTO/ CARL DE SOUZA

US President Barack Obama extends his hand toward a member of the travel pool at the White House Correspondents' Association annual dinner in Washington DC, April 30, 2011. AFP PHOTO / Chris KLEPONIS

US President Barack Obama listens to introductions at the White House Correspondents' Association annual dinner in Washington DC, April 30, 2011. AFP PHOTO / Chris KLEPONIS

US President Barack Obama holds 2-year-old Isaiah Lawrence at the Holt Elementary School in Holt, Alabama, being used as a relief center, as he as tours tornado damage in Tuscaloosa, Alabama, April 29, 2011. Obama Friday toured "heartbreaking" devastation left by murderous tornadoes and storms that killed 313 people, and vowed to help southern communities rebuild. AFP PHOTO / Saul LOEB

US President Barack Obama and daughter Sasha walk across the South Lawn March 23, 2011 upon return to the White House in Washington, DC. Obama was returning to Washington after a 5-day Latin American visit. AFP PHOTO/Mandel NGAN

US President Barack Obama tees off on 10th hole while playing golf at the Mid Pacific Country Club in Kailua, Hawaii, on December 31, 2009. The First Family is on vacation. AFP PHOTO/Jewel SAMAD

US President Barack Obama arrives on the 10th hole to tee off as he plays golf at the Mid Pacific Country Club in Kailua, Hawaii, on December 31, 2009. The First Family is on vacation. AFP PHOTO/Jewel SAMAD

US President Barack Obama leaves after playing golf at the the Mink Meadows Golf Course in Vineyard Haven on Martha's Vineyard, Massachusetts, on August 25, 2009. After a brutal seven months facing economic blight, rising trouble abroad and fighting for an increasingly under-fire agenda, Obama and the First family are on a week-long vacation on the exclusive island of Martha's Vineyard. AFP PHOTO/Jewel SAMAD