A majority of Americans believe the next US president should be careful and not criticize Islam as a whole when speaking about Islamic extremists, according to a latest survey.

The Pew survey stated yesterday that 70 per cent of Democrats and independents who lean towards Democratic party want the next president to refrain from speaking bluntly about Islamic extremism and not criticize Islam as a whole.

However, four-in-ten want the next president to speak bluntly about Islamic extremists even if the statements are critical of Islam as a whole, the survey said, adding that blunt talk is preferred by 65 per cent of Republicans and those who lean toward the Republican party.

The survey also showed that many Americans think a substantial segment of the US Muslim population is anti-American. While 42 per cent of adults say "just a few" Muslims in the country are anti-American (or that none are), 49 per cent of the public believes at least "some" US Muslims are anti-American, including 11 per cent who say "most" or "almost all" US Muslims are anti-American and 14 per cent who think "about half" the US Muslim population is anti-American, it said.