Washington - US President Barack Obama was sworn into office at noon (1700 GMT) Tuesday as the first black president of the United States.

Below is Obama's inaugural address as released in advance by the Presidential Inaugural Committee:

My fellow citizens:

I stand here today humbled by the task before us, grateful for the trust you have bestowed, mindful of the sacrifices borne by our ancestors. I thank President Bush for his service to our nation, as well as the generosity and cooperation he has shown throughout this transition.

World leaders lined up on Tuesday to pay tributes to Barack Obama on the occasion of his inauguration as the 44th president of the United States, with the new president drawing comment from America's allies across the globe - as well as from current enemies.

In the Middle East, where American stock has fallen furthest in recent years, guarded welcome for the president-to-be was evident.

Iran expressed a hope that Barack Obama will "choose the right path" toward Iran, ISNA news agency reported Tuesday.

Cairo  - Across the Arab world, many greeted Barack Obama's victory in the US presidential election with jubilation and relief.

But 10 weeks later, as Obama is sworn into office as the 44th US president and the first African-American to hold the nation's highest office, people from across the Arab world say they are greeting Obama's presidency with diminished expectations.

Wash

Washington  - Moments after taking the oath of office, US President Barack Obama declared Tuesday the United States had ushered in a "new era of peace" and urged Americans to accept a greater responsibility to tackle the vast challenges confronting the nation.

"Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America," Obama told millions of cheering onlookers lined along the National Mall, Washington's vast park that stretches from the inaugural site on the Capitol steps to the Lincoln Memorial.

Paris  - French President Nicolas Sarkozy said Tuesday that he was impatient for US president-elect Barack Obama to take office so that the two of them could "change the world."

"We are eager to see him go to work so that we can change the world with him," Sarkozy said during a stop in the city of Provins.

However, Foreign Minister Bernard Kouchner warned that Obama could not work political miracles.

"He is an exceptional man," Kouchner said, "but he does not have a magic wand."