The exercises were conducted off Hawaii’s coast last week, according to the Pentagon. Combined drills were brought to a halt after 2017 due to a deterioration in relations between Seoul and Tokyo.
Relations between South Korea and Japan reached a low point in 2019 as historical disputes dating back to Japan’s 1910-1945 occupation of the Korean peninsula resurfaced.
However, South Korea’s conservative President Yoon Suk-yeol vowed to improve relations with Japan after he entered office in May.
He also pledged to strengthen ties with Washington to deter action from Pyongyang.
The exercise, which is said to have been a missile warning and ballistic missile search and tracking test, took place between August 8 and 14.
The ministry of defence in Seoul also confirmed the exercise on Tuesday.
It revealed troops would resume long-suspended live field training.
South Korea’s ministry of defence also said further joint military drills would be held between August 22 and September 1.
The news comes after both nations scaled back combined military drills in recent years due to COVID-19.