President Yoon Suk-yeol, center, salutes the national flag at an Armed Forces Day event at the Gyeryongdae military headquarters 160 kilometers south of Seoul on Oct. 1, flanked by Defense Minister Lee Jong-sup, left, and first lady Kim Keon-hee. Yonhap

President Yoon Suk-yeol warned North Korea on Saturday it will be met with a "resolute" and "overwhelming" response if it attempts to use nuclear weapons, shortly after Pyongyang fired two short-range missiles in its fourth such test in less than a week.

The launches further raised tensions as North Korea has appeared to be readying for what would be its seventh nuclear test and recently legalized the use of nuclear weapons in scenarios where its leadership is under threat.

"By adopting its nuclear arms policy into law, it is threatening the survival and prosperity of the Republic of Korea," Yoon said in a speech marking Armed Forces Day at the Gyeryongdae military headquarters 160 kilometers south of Seoul, referring to the South.

"If North Korea attempts the use of nuclear weapons, it will face the resolute and overwhelming response of the South Korea-U.S. alliance and our military," he said.

Yoon also said North Korea's nuclear weapons development defies the international nonproliferation regime and will put the North Korean people's lives in further pain.

"The North Korean regime must even now make the decision to denuclearize for true peace and joint prosperity on the Korean Peninsula," he said.