Barack Obama swears in as the 44th president of the United States of America, on January 20, 2009. (Xinhua)

Barack Obama on Tuesday called for beginning the work of "remaking America" after he was sworn in as the 44th president of the United States on the west front of the U.S. Capitol.

"Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America," Obama told an unprecedentedly massive audience filling up the National Mall in the U.S. capital.

"For everywhere we look, there is work to be done. The state of the economy calls for action, bold and swift, and we will act--not only to create new jobs, but to lay a new foundation for growth," he said.

Obama outlined his to-do list.

"We will build the roads and bridges, the electric grids and digital lines that feed our commerce and bind us together. We will restore science to its rightful place, and wield technology's wonders to raise health care's quality and lower its cost. We will harness the sun and the winds and the soil to fuel our cars and run our factories. And we will transform our schools and colleges and universities to meet the demands of a new age," he said.

"All this we can do. And all this we will do," the president noted.

Earlier, Obama took the oath before John Roberts, chief justice of the Supreme Court.

Despite cold weather, an unprecedentedly massive crowd, estimated to total as much as 2 million people, is gathering in Washington to witness the historic inauguration of Obama, surely to break the historic record of 1.2 million people attending the inauguration of Lyndon Johnson in 1965.

(Xinhua News Agency January 20, 2009)