Almost half of Guam residents are "very concerned" about the Democratic People's Republic of Korea's (DPRK) threat of missile attacks amid the exchange of fierce rhetoric between Washington and Pyongyang, a poll conducted by local media showed.

The online poll through to Thursday evening was conducted by the Pacific Daily News on its official Twitter account. It gave readers three levels to assess their attitudes toward the issue, including very concerned, concerned and not concerned.

Among 3,069 residents who joined the poll, 46 percent selected "very concerned", while 27 percent and 26 percent chose "concerned" and "not concerned" respectively.

The DPRK military said in a statement Thursday that its plan to strike Guam with intermediate missiles would be ready by mid-August and its implementation would depend on a decision by its top leader Kim Jong Un.

It was a response to U.S. President Donald Trump's unusually stern warning to the DPRK on Tuesday, when he said "North Korea (DPRK) best not make any more threats to the United States. They will be met with fire and fury like the world has never seen."

A report of Guam's Pacific News Center website also said local people had different opinions to the threat. Some were scared, but others expressed their full confidence in the capability of the U.S. government.

Local resident Kate Quiambo was quoted as saying that she was so scared that she had planned to leave the island with her family. Meanwhile, Kenneth Leon Guerrero told the reporter that the threat was nothing more than sabre-rattling.

"Well, I am not worried about that because the governor and home security office told us not to worry about that," 64-year-old resident Maria Teehan said in a video clip posted by Pacific Daily News Thursday night. "Even though, I was a little bit upset about our president, because when he fought back with the same kind of language used by North Korea (DPRK), I didn't feel safe."