US President Barack Obama and his Republican rival Mitt Romney have clashed over their economic proposals in the first of three presidential debates.
Mr Romney accused Mr Obama of planning to raise taxes on small businesses in the opening exchanges, but the president said his rival's plan repeated disastrous Bush-era policies.
Mr Obama also argued that his plans would ultimately lead to strong job growth, while Mr Romney accused the president of failing to turn the economy around.
As polls showed Mr Obama with a slight edge among voters ahead of the debate, Mr Romney was the aggressor throughout the 90-minute encounter between the two rivals at the University of Denver.
The two men, standing side-by-side for the first time after months of brutal campaign attacks on each other, clashed over taxes, healthcare and the role of government, reflecting the deep ideological divide in Washington.
Appearing poised and well-prepared, Mr Romney focused on weak economic growth and 8.1% unemployment that has left Mr Obama vulnerable in his effort to win a second four-year term.
Mr Obama charged that Mr Romney's plan to reduce income taxes by 20% across the board and eliminate some tax deductions would leave middle-class Americans paying more taxes, an allegation that Mr Romney denied.
The debate moderated by PBS anchor Jim Lehrer was the best opportunity to date to reach large numbers of voters in an unfiltered way, with an estimated television audience of 60m possible.
A poll for CNN suggests that more than two-thirds of registered voters who watched the debate said that Mr Romney had performed better than Mr Obama.
Both men have been under pressure to provide more specific details on how to get the US economy surging again after a prolonged recovery from recession.
The debate was the first of three such face-offs scheduled in the next four weeks.