A majority also believes for the first time that the United States should "mind its own business," while faulting Obama for his foreign policy, especially over Syria.
The findings are the result of a Pew Research Center poll of some 2,003 people carried out in conjunction with the Council on Foreign Relations between Oct. 30 and Nov. 6.
"For the first time in surveys dating back nearly 40 years, a majority (53 per cent) says the United States plays a less important and powerful role as a world leader than it did a decade ago," the centre, a Washington-based non-partisan think tank, says in its report.