The poll, conducted by Morning Consult and Politico from July 7-9, shows 40 percent of 1,983 respondents regard North Korea as the country's greatest threat.
About 30 percent of survey participants said the Islamic State poses the greatest threat and 16 percent said Russia is the most dangerous country to U.S. national security.
The survey took place not long after North Korea "successfully" launched what it claimed to be an intercontinental ballistic missile, the Hwasong-14, timed to coincide with the Fourth of July.
Americans may also be more wary of North Korea because the nation is increasingly in the news.
The survey shows 83 percent of respondents said they have either heard, read, or seen images of North Korea's missile tests, either "a lot" or "to some degree."
National security is a growing concern, with 21 percent of respondents saying it is the "most important" issue facing the country, up from 18 percent in June.
Nearly half, or 49 percent, of survey respondents said they support military intervention in North Korea. Among those who identified themselves as Republican, 63 percent said they support an air strike on North Korean military facilities, while 40 percent of Democrats said they would support a preemptive attack.
Military actions however, are not the only solution to dealing with North Korea, according to survey responses.
A total of 78 percent polled said they support diplomatic efforts that would compel Pyongyang to give up its nuclear weapons, and 75 percent said they would favor more sanctions.
Respondents were divided on President Donald Trump's approach to North Korea.
Roughly half of the participants said they had a lot or some confidence in Trump's handling of provocations, while 44 percent said they had little confidence in Trump's policies.