A US senator plans to introduce a bill this week that calls for significantly beefing up ground-based missile interceptors in the United States to better defend against North Korea, according to a news report Sunday.

Sen. Dan Sullivan (R-AK) will bring in the legislation that asks for adding an additional 28 Ground-Based Interceptors in Alaska and California, the Hill reported, citing unidentified Senate staffers.

The US currently has 30 interceptors, four in California and the rest in Alaska, and plans to add 14 more by the end of this year, the report said.

"If you want to protect the continental United States, Alaska is literally the front line and the best place and to do that from an attack from North Korea," a Senate staff member familiar with the bill was quoted as telling the newspaper.

"Sullivan is not doing this because it's potentially good for Alaska, he's doing this because (North Korean leader) Kim Jong-un is continuing to test and advance his programs," the official said.

The legislation would also ask the Missile Defense Agency to speed up the development of new missile interceptors by accelerating testing, while calling for the agency to review the possibility of buying more of the current interceptors, according to the Hill.

Concerns about North Korean nuclear and missile threats have deepened in the US since the North's leader said in his New Year's Day address that the country is ready to test-fire an intercontinental ballistic missile apparently capable of reaching the US. (Yonhap)