Moments after taking the oath of office to become the 44th president, Mr Obama called for “a new era of responsibility” and for changes in US policy areas from the economy to climate change and the struggle against Islamist extremism.

“The world has changed, and we must change with it,” Mr Obama declared before an exuberant crowd of hundreds of thousands that gathered in Washington's National Mall to mark the inauguration of the country's first African-American president. “Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America.”

While stressing that America “would not apologise” for its values and way of life or waver in its fight against terrorism, Mr Obama signalled a new desire to work with other nations. “Earlier generations faced down fascism and communism not just with missiles and tanks, but with sturdy alliances and enduring convictions. They understood that our power alone cannot protect us, nor does it entitle us to do as we please.”