The Defense Department has ended its role in the search-and-rescue efforts following the disappearance of a Japanese F-35A Joint Strike Fighter last week, but continues to work with its Japanese counterparts to assist as needed, officials said this week.

Acting Pentagon Spokesman Charles Summers said in a statement to reporters Thursday evening that the U.S. search and rescue efforts have ceased, but the department will continue to coordinate with Japan on efforts to locate and recover the aircraft.

The aircraft, designated AX-6, is the second F-35A assembled at Mitsubishi Heavy Industries’ F-35 Final Assembly & Check-Out (FACO) facility in Nagoya, Japan and is the first to be assigned to the JASDF’s 3rd Air Wing, 302nd Tactical Fighter Squadron, Misawa Air Base, Japan.

The Japanese Air Self-Defense Force said April 9 that it lost contact with an F-35A over the Pacific Ocean, about 85 miles away from Misawa City (Defense Daily, April 9). The BBC reported the following day that parts of the aircraft were found in the ocean, leading officials to deduce that a crash occurred.

“The U.S., and all F-35 partners, remain fully committed to protecting all F-35 capabilities and technology,” Summers said in the Thursday statement. “Our thoughts continue to be with the family, friends and colleagues of the missing pilot.”

The Pentagon continues to have “full faith and confidence” in the F-35 program, he added. “All 276 U.S. F-35’s continue to fly, including U.S. Air Force F-35As in the U.S. CENTCOM area of responsibility.”

Acting U.S. Defense Secretary Patrick Shanahan and Japanese Defense Minister Takeshi Iwaya told reporters Friday at the Pentagon that they were not worried that the Chinese might find the missing F-35 before Japanese or allied forces.

“We don’t have such possibility,” Iwaya said via an interpreter. “We are conducting surveillance and warning activities so we can identify and find the missing aircraft.”

Shanahan noted that the Japanese are taking the lead on the investigation, and that the Defense Department is working “very collaboratively” with them.

“We have got a capability if what they have doesn’t prove to be sufficient,” he added.

The aircraft, manufactured by Lockheed Martin [LMT], was part of Japan’s first operational F-35A unit, the JASDF’s 302nd Squadron operating from Miwasa Air Base. Tokyo plans to eventually procure up to 105 F-35As and 42 F-35Bs.

Meanwhile, the U.S. and Japanese diplomatic and defense leaders reaffirmed their commitment to cross-domain partnership in a joint meeting Friday at the State Department.

According to a joint press statement from U.S. Secretary of State Mike Pompeo, Japanese Foreign Minister Taro Kono, Shanahan and Iwaya, “The Ministers affirmed that their two nations’ strong bilateral security relationship continues to be the foundation of the U.S.-Japan Alliance. As such, the Ministers decided that cooperation in cross-domain operations, enhancing the Alliance’s capabilities, and increasing operational readiness and cooperation should be core objectives to advance our defense relationship.”

The ministers expressed concern about “rapidly evolving technological advancement” in domains such as space, cyberspace, and the electromagnetic spectrum, the release said. “The Ministers highlighted the need to address these challenges jointly to ensure the Alliance’s superiority in a contingency and to safeguard our institutions and rules-based order during peacetime,” it said.