Seoul says discussions for cooperative nuclear drills in progress

The statement was released after Biden said the United States was not discussing joint nuclear exercises with South Korea, seemingly contradicting comments by Seoul's President Yoon Suk-yeol earlier this week.

The two security allies are "in talks over information-sharing, joint planning and the joint implementation plans that follow with regard to the operation of US nuclear assets to respond to North Korea's nuclear weapons", Yoon's office said in a statement.

In an interview with the Chosun Ilbo newspaper published Monday, Yoon said the United States' existing "nuclear umbrella" and "extended deterrence" were no longer enough to reassure South Koreans.

"The nuclear weapons belong to the United States, but the planning, information sharing, exercises and training must be done jointly by South Korea and the United States," Yoon said, adding that the US was "quite positive" about the idea.

Hours after that interview was published, Biden gave an emphatic "no" in response to a question on whether the two sides were considering joint nuclear exercises.

Yoon's office acknowledged Biden's response but said the US president had been "left with no options but to answer 'No' when directly asked... without any context".

"Joint nuclear exercise is a term only used by nuclear powers," said Kim Eun-hye, a spokeswoman for the South Korean president's office.

The back and forth comes after the North's leader Kim Jong Un called for an "exponential" increase in his country's nuclear arsenal and new intercontinental ballistic missiles (ICBMs) to counter what it termed US and South Korean hostility.

In 2022, the North conducted sanctions-defying weapons tests nearly every month, including firing its most advanced ICBM ever.

Under the hawkish Yoon, South Korea has beefed up joint military drills with the United States, which had been scaled back during the pandemic or paused for a bout of ill-fated diplomacy with the North under his predecessor.