A former US ambassador to South Korea called Tuesday for beefed-up defense drills between Seoul and Washington to counter North Korean threats, stressing the pursuit of dialogue with the recalcitrant regime should not come at the expense of the allies' military readiness.

Retired Adm. Harry Harris, who served as US ambassador to South Korea from 2018-2021, made the call, pointing to North Korean leader Kim Jong-un's unrelenting focus on advancing his regime's nuclear program and other weapons projects.

"The quest for dialogue with the North must never be made at the expense of the ability to respond to threats from the North," he said during a virtual forum hosted by The Washington Times Foundation, a US-based nonprofit organization.

"We must up our combined game. Deterrence by appeasement is not deterrence at all," he added, underscoring that dialogue and military readiness must go "hand in hand."

Harris noted that last year alone, Pyongyang launched dozens of ballistic missiles of "increasing complexity" and traded weapons for Russian technology to conduct a satellite launch.

"Clearly, this is no path towards peace," he said. "While we hope for diplomacy with North Korea to be successful, we must recognize that hope alone is not a course of action."

Harris also expressed concerns over South Korean Foreign Minister nominee Cho Tae-yul's recent remarks in pursuit of improved relations with China.

"He seeks to strike an equivalency between China and the United States," he said. "There is no equivalency. South Korea has only one ally that will have its back if North Korea invades, and China is not that country."

Prior to his ambassadorial stint, Harris served as the head of the US Pacific Command, currently the Indo-Pacific Command, an umbrella unit that oversees the 28,500-strong US Forces Korea. (Yonhap)