North Korea's rapid progress in developing nuclear weapons and missiles capable of reaching the United States mainland has fuelled a surge in regional tension and UN-led sanctions appear to have failed to bite deeply enough to change its behaviour.
The U.N. Security Council unanimously imposed new sanctions on North Korea on August 5 that could slash its $3 billion annual export revenue by a third.
The "lax enforcement" of existing sanctions and Pyongyang's "evolving evasion techniques" were undermining the United Nations goal of getting North Korea to abandon its nuclear and ballistic missile programmes, Kyodo quoted the report as saying.
DPRK media outlet Korean Central News Agency warned in a brief statement that the exercises would "further drive the situation on the Korean Peninsula into a catastrophe".
Unlike the March exercise, UFG doesn't include live fire drills and happens concurrently with drills by local governments and civil servants to prepare South Korea's civil defenses.
Last month, South Korea too formally proposed opening talks with North Korea to reduce tensions along the border after North Korean defiant regime successfully launched an ICBM having capability of striking Alaska in the US.
It involves tens of thousands of South Korean soldiers.
Moon said North Korea should neither distort South Korea's efforts to maintain peace nor indulge in provocative acts, which worsen situations, under the pretext of this exercise.
"The drills deal with all the steps involved in a war, of course, towards victory", said Moon Seong-mook, a retired South Korean brigadier who regularly participated in the drills until the mid-2000s. However, the US and South Korea maintain they are purely defensive.
The 1950-53 conflict in the region, also known as "The Forgotten War" or "The Unknown War" due to low public attention it received during and after the war, saw more than one million deaths.
The Ulchi Freedom Guardian drills are largely computer-simulated war games held every summer and have drawn furious responses from North Korea, which views them as an invasion rehearsal.
Mr. Turnbull responded by urging the global community to "bring North Korea to its senses".
"If North Korea provokes again, it will face with much harsher sanction and won't stand it in the end".
The writer is a Doha-based journalist.