Funding for the $1.9 billion Homeland Defense Radar- Hawaii has again been zeroed out in the U.S. Missile Defense Agency’s proposed budget — a position that reflects evolving and competing defense priorities and could set up another challenge in Congress.

Both the Hawaii radar, which was to be used to better track North Korean intercontinental ballistic missile threats, and a separate Pacific radar have been shelved by the Defense Department.

“There have been no changes in budget for these two radars since the budgets were zeroed” in last year’s fiscal 2021 request, Heather Cavaliere, a Missile Defense Agency spokeswoman, said in an email.

U.S. Sen. Mazie Hirono, D-Hawaii, said the Department of Defense “previously identified the Homeland Defense Radar-Hawaii (HDR-H) as the capability it needed to protect Hawaii in response to an increasingly credible North Korean ballistic missile threat.”

“Last year when this happened, DOD did not satisfactorily explain why it cut funding for HDR-H in its proposed budget, prompting Congress to reverse the Trump Administration’s request and fund the project at $133 million,” Hirono said in a statement. “Once again, DOD has also yet to adequately explain how Hawaii will be protected without HDR-H and whether our state will have the same level of protection as the rest of the United States.”

Hirono said U.S. Indo-Pacific Command, the Missile Defense Agency and the incoming commander of U.S. Forces Korea “have all identified HDR-H as a priority for the protection of Hawaii.”

“If DOD has new analysis and wants to propose a new system to achieve the same capability, I welcome the chance to hear about it,” the senator said. “However, in an increasingly unpredictable region, now is not the time to cut funding for missile detection technology without an assurance of enhanced protection from another source.”

U.S. Reps. Kai Kahele and Ed Case, also Hawaii Democrats, said in a joint statement, “The Department of Defense owes a clear explanation as to why we should abandon the Homeland Defense Radar-Hawaii, a project Congress mandated the military construct in 2016 and that the department has made clear is critical to our national security and repeatedly prioritized since FY 2017.”

The pair noted that in testimony to Congress in March, Adm. Phil Davidson, then head of U.S. Indo-Pacific Command, said the Hawaii radar “supports the best-programmed solution to enable a credible, in-depth, under layer defense for our forces in Hawaii.”

“Until the Department of Defense can provide Congress a credible and currently deployable missile defense alternative to protect every resident of Hawaii and our nation’s Indo-Pacific military commands, the project should continue,” the two lawmakers said.

The Honolulu Star-Advertiser reported in April that funding was expected to be absent again for fiscal 2022. The Defense Department unveiled a proposed $715 billion budget Friday.

“I’m sure Congress will take a look at the issue again this year. Nevertheless, global sensor management for the various missile defense missions remains a challenge,” said Tom Karako, director of the Missile Defense Project at the Center for Strategic and International Studies. “For the Hawaii (ballistic missile defense) radar, the multitude of factors include topline budget pressure, threat assessment, competing missions, and local constituencies.”

Kahuku Training Area on Oahu and the Pacific Missile Range Facility on Kauai are the two locations that were still under consideration for the powerful radar, which was planned to have a single face up to 85 feet tall. Community opposition emerged on Oahu.

The Missile Defense Agency said it is using the $133 million congressional “plus up” for production of “critical radar components” and studies “for the siting and development of the (radar) — should a deployment decision be made and is funded.”

Testifying last year before a congressional committee, Missile Defense Agency Director Vice Adm. Jon Hill said the U.S. was at an “inflection point” that was complicating missile defense.

“Ballistic, hypersonic and cruise missiles are becoming more capable of carrying conventional and mass destruction payloads farther, faster and with greater accuracy,” he said in prepared remarks.

Russia and China continue to develop advanced missiles designed to overfly air defense sensors and fly below ballistic missile sensors, he said.

Missile defense will “continue to leverage space-based, ground-based and maneuverable sea-based sensors,” Hill said. “Yet there will never be enough terrestrial-based sensors to track maneuvering missiles in large numbers. If we are to outpace the threat, we need a persistent space-based global sensor capability.”

A Missile Defense Agency overview for its $8.9 billion fiscal 2022 budget request states that U.S. missile defense policy is aimed at protecting against “rogue” state efforts such as those of North Korea and Iran.

“The United States is not developing or deploying missile defense capabilities designed to counter nuclear intercontinental-range missile threats from near-peers Russia and China,” the agency said. Those are far too complex to effectively intercept.

But to address “regional” threats, U.S. missile defense policy seeks to defend against a “full range” of enemy missiles.

The agency said in particular it is “supporting efforts to improve the warfighter’s capability to defend Guam against regional cruise, ballistic and hypersonic missiles.”

The Defense Department said it is seeking $5.1 billion in funding in 2022 for the Pacific Deterrence Initiative — a measure put in place last year to boost defense spending in the era of “great power” competition with China.

An Indo-Pacific Command needs assessment said that the most important action the U.S. can take to increase lethality is to invest $1.6 billion in a 360-degree air defense capability on Guam — noted as the “most crucial operating location in the western Pacific.”

In the meantime, Hawaii relies on a network of smaller radars as well as the Sea-Based X-Band Radar should a North Korean threat become imminent — and experiences a gap in radar coverage while doing so.

A 2018 Defense Department report said the Pacific Discriminating Radar Program included the Hawaii and Pacific radars and was intended to address “requirements for a near-term persistent solution against advancing threats and closes capability gaps throughout the Pacific region.”