The ministry and USFK did not immediately comment, but the reports came after US President Donald Trump instructed the Pentagon to "substantially reduce" the drills, and said North Korean leader Kim Jong-un had responded to his outreach.
Trump had cited what he said was a good relationship with Kim and South Korea's refusal to join the US war against Iran.
Trump's move was apparently taken without consultations with South Korea, deepening concerns about the reliability of the US-South Korean alliance forged in the turmoil of the 1950-53 Korean War.
Earlier on Tuesday, South Korean President Lee Jae-myung called for stronger independent defence capabilities, while saying annual civil-defence exercises held alongside the joint military drills were defensive and not intended to threaten North Korea.
Lee said Seoul should proceed without disruption with the planned transfer of wartime operational control from the United States during his term, in line with the government's existing plan.
"A strong alliance makes the foundation of security stronger, and strengthening our own capabilities increases our value and necessity as an ally," Lee said in a cabinet meeting, describing the US-South Korea alliance and independent defence as mutually reinforcing.
Lee said maintaining peace was the government's top priority, but South Korea also needed to prepare for a "worst-case scenario", underscoring the need for stronger military capabilities of its own.
He also called for faster progress on South Korea's nuclear-powered submarine program and for developing officers capable of integrated operations, as distinctions between battlefields become less clear.
At a National Security Council meeting on Tuesday, Lee said the civil-defence exercises held alongside major US-South Korea military drills were defensive in character.
South Korea had no intention of using the exercises to attack North Korea or raise tensions on the Korean Peninsula, Lee said, adding that their purpose was to protect citizens' daily lives rather than target any particular party as an enemy, according to a statement by the presidential Blue House.
In a separate briefing on Tuesday, South Korean National Security Adviser Wi Sung-lac said Seoul hoped Trump's message would help revive dialogue between Washington and Pyongyang.
"We hope the friendly relationship between the US and North Korean leaders will lead to meaningful North Korea-US dialogue," Wi told reporters.
Such engagement, he said, could bring tangible progress toward peace and stability on the Korean Peninsula and help restart broader discussions.
Discussions over the joint military exercises come ahead of a visit by Chinese Foreign Minister Wang Yi to South Korea on Wednesday and Thursday for talks expected to cover developments on the Korean Peninsula and regional security issues.
The presidential office has also said it would continue co-ordinating closely with Washington on the allies' combined defence posture and military exercises.
The annual Ulchi Freedom Shield exercises began on Monday and are scheduled to run through August 27.
with AP
