Defense Minister Lee Jong-sup visited the Navy's submarine unit Thursday and called on troops to maintain a "full" combat readiness posture, his office said.

His visit to the Submarine Force Command in Changwon, 398 kilometers southeast of Seoul, came amid concerns that North Korea could make provocations in response to a major South Korea-US military exercise set to begin next week.

"You should not only maintain a full combat readiness posture ... on a day-to-day basis but also maximize mental strength to gain a firm will for combat even in the most extreme circumstances," Lee was quoted as saying.

There, the minister was briefed on the command's operational activities and held a meeting with its members on their working conditions and other issues.

"I feel so proud to see you all, who are firmly undergirding 'peace through strength' as (the members of) a national strategic unit," Lee said.

Lee also said he would make efforts to improve troops' working conditions through such measures as improving the wage system for entry-level non-commissioned officers amid recent criticism over their relatively low pay. (Yonhap)