A House bill co-sponsored by U.S. Reps. Colleen Hanabusa and Tulsi Gabbard calls for an additional 28 ground-based interceptors to protect against North Korean threats and requires the further study of using new SM-3 IIA missiles or other interceptors for the defense of Hawaii.

“In light of the North Korean threat, the additional ground-based interceptors at Fort Greely, Alaska, are especially essential for the defense of the United States, our states and allies,” Hanabusa said Friday in a release. “This act furthers the long-standing tradition of Alaska and Hawaii pulling together for the good of the United States.”

The “Advancing America’s Missile Defense Act of 2017” is a House companion to Senate legislation introduced in May and co-sponsored by U.S. Sens. Brian Schatz and Mazie Hirono, also members of Hawaii’s Democratic congressional delegation.

“This bill will help improve our ability to defend Hawaii, Alaska and the U.S. mainland against a North Korean ballistic missile threat,” Schatz said last month. “While we take this extra step to strengthen our defense capabilities, we must continue to explore every diplomatic avenue to hold North Korea to its international commitments and stop its unlawful pursuit of a nuclear-capable ballistic missile.”

The United States has 36 operational ground-based defensive missiles at Fort Greely and Vandenberg Air Force Base in California that are intended to protect Hawaii and the mainland from a North Korean missile strike. That number is being increased to 44 by the end of the year.

Navy Vice Adm. James Syring, who just stepped down as director of the U.S. Missile Defense Agency, noted the successful May 30 flight test of a California-based interceptor that destroyed a simulated North Korean intercontinental ballistic missile over the Pacific that was launched from Kwajalein Atoll.

The agency will begin deliveries this year of nine new interceptors configured with CE-II Block 1 “kill vehicles” with new alternate divert thrusters and three-stage C2 booster vehicles “following this successful intercept flight test of these new components,” Syring said in written comments before a congressional committee June 7.

The Missile Defense Agency has a budget request of $7.9 billion for fiscal 2018, and Syring was asked at the hearing whether the amount keeps the United States “paced ahead of the threat.”

“I would not say that we are comfortably ahead of the threat,” Syring said. “I would say we are addressing the threat that we know today. And the advancements in the last six months have caused great concern to me and others in the advancement of and demonstration of technology — ballistic missiles from North Korea.”

The Senate bill states that since 2006 and adjusted for inflation, funding for the Missile Defense Agency has decreased 23.4 percent to $8.4 billion from $11 billion.

Syring was asked about the defense of Hawaii and using the new SM-3 Block IIA missile, which will soon be tested again off Hawaii.

There is “inherent capability to engage longer-range threats,” Syring said, adding that “analysis indicates that that could add another layer of defense to Hawaii.”

The nonprofit Missile Defense Advocacy Alliance said the land-based Aegis Ashore missile test facility on Kauai could be used to provide that second layer of defense at less cost with ground-based interceptors at $80 million and SM-3 IIAs at $20 million.

The Senate bill also calls for the study of procuring up to 100 more ground-based interceptors to be distributed across the United States with the possibility of the missiles being transportable.