WASHINGTON - Le président américain Barack Obama a prêté serment dimanche lors d'une cérémonie intime à Washington, amorçant officiellement son second et dernier mandat à la tête des États-Unis.

M. Obama a été assermenté par le président de la Cour suprême, John Roberts, dans la Salle bleue de la Maison-Blanche. Posant sa main droite sur une Bible utilisée depuis des années par sa belle-famille, il a juré de soutenir et défendre la Constitution des États-Unis, reprenant les paroles prononcées par ses 43 prédécesseurs.

La brève cérémonie s'est déroulée en présence d'une dizaine de proches du président, dont son épouse, Michelle, ses deux filles, Malia et Sasha, ainsi que sa soeur Maya Soetoro-Ng. La mère et le frère de la première dame, Marian et Craig Robinson, ont également assisté à l'événement, de même qu'une poignée de journalistes.

Barack Obama prêtera de nouveau serment lundi, cette fois-ci à l'extérieur du Capitole devant une foule de plusieurs centaines de milliers de personnes. L'assermentation de dimanche était une formalité. Selon la Constitution américaines, les présidents commencent automatiquement leur mandat à midi le 20 janvier. Étant donné que cette date tombait un dimanche cette année, jour où il n'y a traditionnellement pas de cérémonie d'investiture, les responsables ont organisé un second événement public lundi.

Le vice-président Joe Biden a pour sa part été assermenté dimanche matin à l'Observatoire naval des États-Unis, sa résidence officielle, dans le nord-est de Washington. L'homme de 70 ans a prêté serment la main posée sur une Bible appartenant au clan Biden depuis 1893 et devant la juge de la Cour suprême Sonia Sotomayor. Nommée par Barack Obama, Mme Sotomayor est la première personne d'origine hispanique à avoir été affectée au plus haut tribunal du pays.

Avant son assermentation dimanche, le président a rendu hommage aux soldats ayant donné leur vie pour les États-Unis lors d'une cérémonie au cimetière national d'Arlington à laquelle a aussi participé le vice-président. M. Obama et sa famille ont ensuite assisté à un office religieux en mémoire de Martin Luther King. L'investiture publique de lundi coïncide en effet avec le jour férié célébrant l'anniversaire du défenseur des droits civiques assassiné en 1968.

Le président avait amorcé son week-end d'assermentation en participant samedi à la Journée nationale de service communautaire durant laquelle Michelle et lui ont notamment aidé à repeindre une école élémentaire.

Barack Obama et Joe Biden s'adresseront à leurs partisans dimanche soir durant une réception organisée pour souligner leur investiture.

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  • Barack Obama (2009)

    Barack Obama delivers his inaugural address after being sworn in as 44th U.S. president at the Capitol in Washington on January 20, 2009.

  • George W. Bush (2005)

    U.S. President George W. Bush delvers his inauguration speech on Jan. 20, 2005 in Washington.

  • George W. Bush (2001)

    President George W. Bush stands at the podium before giving his inaugural address on January, 20 2001 at the U.S. Capitol in Washington.

  • Bill Clinton (1997)

    President Bill Clinton calls for national unity during his Jan. 20, 1997 inaugural address on Capitol Hill in Washington.

  • Bill Clinton (1993)

    President Bill Clinton delivers his inaugural address after being sworn in on Jan. 20, 1993 in Washington.

  • George H.W. Bush (1989)

    U.S. President George Herbert Walker Bush addresses the audience outside the Capitol on Jan. 20, 1989 in Washington.

  • Ronald Reagan (1985)

    Ronald Reagan delivers his inaugural address in the Rotunda of the Capitol on Monday, Jan. 21, 1985 in Washington.

  • Ronald Reagan (1981)

    President Ronald Reagan waves with his wife, Nancy, after being sworn in as 40th president of the United States on Jan. 20, 1981.

  • Jimmy Carter (1977)

    Jimmy Carter is shown in January 1977, speaking after taking the oath of office as President of the United States.

  • Richard Nixon (1973)

    President Richard M. Nixon delivers his inaugural address on January 20, 1973 in Washington.

  • Richard Nixon (1969)

    President Richard M. Nixon dedicates his new administration to the cause of "peace among nations" as former President Lyndon Johnson, right, listens to the inaugural speech Jan. 20, 1969 in Washington.

  • Lyndon Johnson (1965)

    President Lyndon B Johnson is shown as he waves goodbye to crowds from the presidential reviewing stand, after the long day of inaugural parades, on Jan. 20, 1965 in Washington.

  • John F. Kennedy (1961)

    This Jan. 20, 1961 black and white file photo shows U.S. President John F. Kennedy delivering his inaugural address after taking the oath of office at Capitol Hill in Washington.

  • Dwight Eisenhower (1957)

    President Dwight D. Eisenhower was all smiles at end of public oath-taking for second term of office at Capitol on Jan. 21, 1957 in Washington.

  • Dwight Eisenhower (1953)

    President Dwight D. Eisenhower and the country's new first lady, Mamie, wave to spectators from an open car as they leave the Capitol at the start of the inauguration parade, January 20, 1953.

  • Harry Truman (1949)

    President Harry S. Truman delivers inaugural address from Capitol portico, January 20, 1949, after taking oath of office for his first full term as chief executive.

  • Franklin D. Roosevelt (1945)

    Franklin Delano Roosevelt, President of the United States of America, speaking during his fourth inauguration ceremony.

  • Franklin D. Roosevelt (1941)

    President Franklin Roosevelt speaking from the inaugural stand on Jan. 20, 1941.

  • Franklin D. Roosevelt (1937)

    President Franklin D. Roosevelt and first lady Eleanor Roosevelt are seen up Pennsylvania Avenue during the inaugural parade in Washington, Jan. 4, 1937.

  • Franklin D. Roosevelt (1933)

    President Franklin D. Roosevelt speaks at the podium during his March 4, 1933 inaugural address in Washington.

  • Herbert Hoover (1929)

    President Herbert Hoover delivers his inaugural speech on March 4, 1929 at the Capitol in Washington.

  • Calvin Coolidge (1925)

    Calvin Coolidge at his inauguration on March 4, 1925 in Washington.

  • Warren G. Harding (1921)

    The 29th American President, Warren Gamaliel Harding (1865 - 1923), delivering his inaugural address from a stand at the East portico of the Capitol building on March 4, 1921 in Washington.

  • Woodrow Wilson (1917)

    This general view shows the second inauguration of President Woodrow Wilson on March 5, 1917 in Washington.

  • Woodrow Wilson (1913)

    Former American President William Howard Taft (1857 - 1930), right, and Woodrow Wilson (1856 - 1924), at Wilson's inauguration as the 28th President of the United States of America.

  • William Howard Taft (1909)

    William Howard Taft at his inauguration on March 4, 1909 in Washington.

  • Theodore Roosevelt (1905)

    The inauguration of President Theodore Roosevelt, 1905.

  • William McKinley (1901)

    American President William McKinley (1843 - 1901) leaving for the Capitol for his inauguration for a second term.

  • William McKinley (1897)

    In this image provided by the Library of Congress Major William McKinley takes his oath of office during the 1897 inauguration in Washington.

  • Grover Cleveland (1893)

    President Grover Cleveland reads his inaugural address from the steps of the Capitol building on March 4, 1893 in Washington.

  • Benjamin Harrison (1889)

    This drawing depicts the inauguration of Benjamin Harrison as he takes the oath of office on March 4, 1889 in Washington.

  • James Garfield (1881)

    This general view shows the inauguration of James A. Garfield, the nation's 20th president, on March 4, 1881 in Washington.

  • Rutherford B. Hayes (1877)

    The public inauguration of Rutherford B. Hayes takes place in front of the U.S. Capitol on March 5, 1877 in Washington, D.C.

  • Ulysses S. Grant (1873)

    This artist's rendition shows the second inauguration for Ulysses S. Grant as he takes the oath of office on March 4, 1873 in Washington.

  • Ulysses S. Grant (1869)

    Photo shows Inauguration Day, March 4, 1869, when Ulysses S. Grant took the oath of office as the 18th President of the United States.

  • Abraham Lincoln (1865)

    A scene in front of the East front of the U.S. Capitol is seen during President Abraham Lincoln's second inauguration, 1865, just six weeks before his assassination.

  • Abraham Lincoln (1861)

    Abraham Lincoln takes the oath of office as the 16th president of the United States on March 4, 1861 in Washington.

  • James Buchanan (1857)

    President James Buchanan delivers his address after being sworn in as the 15th president of the United States on March 4, 1857 in Washington.