Fifty-five percent of people who participated in the Rasmussen Report poll released Monday said they favor creating a U.S. anti-missile defense system, while 16 percent said they were opposed, results indicated.
Twenty-nine percent said they were undecided.
President Obama recently drew criticism from political opponents after an open microphone caught him telling Russian President Dmitry Medvedev that U.S.-Russian missile defense negotiations have to wait until after the Nov. 6 general elections, when the president should have more "flexibility."
Washington has said the missile defense shield would ensure safety for Europe in the event of an attack from Iran. Moscow has opposed the system, fearing it would be used against Russia and its interests.
Results are based on a nationwide telephone survey of 1,000 likely voters conducted last Thursday and Friday. The margin of error is 3 percent.