U.S. Rep. Mark Takai said Thursday that the Defense Department has to be “more proactive” in looking at possibly operating the Aegis Ashore missile site on Kauai not just for testing, but also to protect Hawaii from ballistic missile threats.

Takai, a Hawaii Democrat, said he also wants to get a missile-discriminating radar in Hawaii to aid with that defense.

“I think we can’t wait until North Korea launches something that has precision that can detect and hit something similar to Hawaii,” Takai said at the House Armed Services subcommittee hearing.

The “missile defeat posture and strategy” was discussed as a part of the fiscal 2017 president’s budget request. The Kauai facility was put in place to test defensive Aegis Ashore sites for Romania and Poland.

Converting the Kauai site to an actual defensive use has been studied before — with a startup cost estimated at $41 million. But there are challenges to doing so, including needing a missile-discriminating radar, extra staffing, alternating missile systems testing with an actual defense posture, and certifying Aegis Ashore is capable against intercontinental ballistic missiles.

“Operationalizing an Aegis Ashore site is no easy step,” said Navy Vice Adm. J.D. Syring, head of the U.S. Missile Defense Agency.

Takai noted that an Air and Missile Defense Radar, or AMDR, prototype is being tested at the Pacific Missile Range for Navy ships that would also “provide significant capability to detect and track advanced long-range ballistic missile threats” to Hawaii.

The scalable radar offers greater detection ranges and increased missile discrimination accuracy compared with radars currently aboard Navy destroyers.

The prototype will be moved from Kauai in 2017, and Takai said he submitted an amendment for advance funding for planning and design to get a discriminating radar to Hawaii faster.

“Are you supportive of this effort?” he asked Syring.

Syring said U.S. Pacific Command head Adm. Harry B. Harris Jr. “has been open about the need for additional sensor capability in Hawaii, and we are obviously very well aware of that requirement and are looking at what the sensor options could be. But right now it (Aegis Ashore) is a test site.”

A discriminating radar for Hawaii is seen in the short run as a beneficial link to ground-based interceptor missiles in Alaska and California that protect the United States from ballistic missile threats.

The Sea-Based X-Band Radar is seen as having limitations in that it has to be moved far out to sea, while its technology also has limited use.

In response to another question from Takai about certifying the Aegis Ashore facility for ballistic missile threats, Syring said, “Right now there are no plans to do it.”

Harris said in January that consideration should be given to enabling Aegis Ashore to protect against North Korean threats.

Syring said discussions with Harris have included “what additional sensor capability can we provide the existing ground-based midcourse defense system (in Alaska and California) in terms of more capability against a more complex threat for Hawaii specifically.”

The Aegis Ashore site on Kauai uses a land-based SPY-1 radar and SM-3 missiles like those on 33 U.S. Navy Aegis ships with ballistic missile shoot-down capability. Riki Ellison, chairman of the nonprofit Missile Defense Advocacy Alliance, said last month that Hawaii lags in ballistic missile defense while the United States pours billions into defensive additions in Alaska and the mainland, Guam, Japan and South Korea.

An operational Aegis Ashore on Kauai could provide at least two more shot opportunities to knock out a North Korean missile in the terminal phase of flight, according to Ellison’s organization.