Washington  - More than two thirds of Americans think Barack Obama is doing a good job, according to a US poll released on the eve of the president's 100th day in office.

The nationwide survey by the US television network CBS and the New York Times, conducted April 22-26 among 973 adults, found that while Obama earns high marks from Democrats and independents, he remains unpopular among Republicans, less than one third of whom approve of the president's job performance so far.

Obama's 68 per cent approval rating at the 100 day mark surpasses the ratings of his two immediate predecessors, George W Bush (56 per cent) and Bill Clinton (49 per cent).

Only two presidents in the past half century - John F. Kennedy (83 per cent) and Dwight Eisenhower (72 per cent) - had a higher approval rating at this point in their presidencies. (dpa)