Barack Obama sworn in as U.S. president, calls for 'remaking of America'

Americans need to embrace a "new era of responsibility" to remake the United States in the face of military, economic and domestic challenges, U.S. President Barack Obama said Tuesday in his inauguration address.

"Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America," said Obama, who spoke before more than one million people crowded into Washington's National Mall, a park that stretches from the Lincoln Memorial to the Capitol.

Obama made the historic address shortly after he held his right hand in the air and placed his left hand on Abraham Lincoln's inaugural Bible to take the oath of office and become the first black president of the United States.

"What is required of us now is a new era of responsibility — a recognition, on the part of every American, that we have duties to ourselves, our nation, and the world," he said. "Duties that we do not grudgingly accept but rather seize gladly, firm in the knowledge that there is nothing so satisfying to the spirit, so defining of our character, than giving our all to a difficult task. This is the price and the promise of citizenship."

Obama, a Democrat who succeeded Republican George W. Bush as president, acknowledged his oath was administered "amidst gathering clouds and raging storms" — an economy in crisis, costly health care, a faltering school system and environmental threats.

"That we are in the midst of crisis is now well understood," said Obama. "The challenges we face are real.

"But know this America — they will be met," he said, drawing a massive cheer from the crowd.

Obama vowed to rebuild infrastructure, invest in scientific research, improve health care and find new sources of energy.

"Those who manage the public's dollars will be held to account," he said.

Obama also issued a blunt warning to those who threaten the United States: "We will not apologize for our way of life, nor will we waver in its defence, and for those who seek to advance their aims by inducing terror and slaughtering innocents, we say to you now that our spirit is stronger and cannot be broken; you cannot outlast us, and we will defeat you."