A South Korean navy P-3 Orion visits Marine Corps Base Hawaii, June 26, 2018. (Breanna Ancheta/U.S. Navy)

CAMP HUMPHREYS, South Korea — The United States and South Korea are discussing ways to support Seoul’s reconnaissance operations following last week’s crash of a South Korean naval spy plane that killed four crew members, according to the South’s military.

Talks are underway to use patrol aircraft assigned to U.S. Indo-Pacific Command to offset the loss of the P-3CK Orion that went down Thursday, South Korean army Col. Lee Sung-jun, a spokesman for the Joint Chiefs of Staff, said at a news conference Monday in Seoul.

INDOPACOM did not immediately respond to an email requesting comment Monday evening in Hawaii.

The Orion crashed into a mountain in Pohang, about 170 miles southeast of Seoul, six minutes after taking off from the city’s naval base for a routine training mission, South Korea’s Ministry of National Defense said Friday.

Two naval officers and two noncommissioned officers were killed. The sailors were posthumously promoted, and a memorial service was held Sunday in Pohang, the ministry said.

South Korea’s fleet of 16 Orion aircraft has been grounded pending an investigation. In the meantime, maritime helicopters, ships and other “alternative forces” are being used to maintain surveillance operations, Lee said.

Seoul is preparing to field its first P-8A Poseidon aircraft next month, Lee said. South Korea purchased six of the Boeing-manufactured aircraft from the U.S. in 2018 for $2.1 billion, according to a Defense Security Cooperation Agency news release that fall.

The P-8 is expected to replace the aging P-3 fleet, which has been in service with South Korea’s navy since 1995. It originally entered U.S. Navy service in 1962 and was designed to detect and track enemy submarines during the Cold War, according to its manufacturer, Lockheed Martin.

Stars and Stripes reporter Yoojin Lee contributed to this report.