South Korea and the United States have been discussing the latter's nuclear policy review on "various occasions," a Seoul official said Sunday, amid reports that Washington is mulling a policy shift feared to weaken military deterrence.

The Financial Times reported Saturday that US allies have been lobbying President Joe Biden not to alter America's policy on the use of nuclear weapons, amid speculation he is considering a "no-first-use" approach that critics say could embolden China and Russia.

The report came as conservatives here have called for strengthening the credibility of the US nuclear umbrella for South Korea at a time when North Korea has been doubling down on its nuclear and missile programs.

"We have been discussing it with the United States on various occasions," a foreign ministry official said on condition of anonymity. "The US side has been sharing with us information related to its ongoing nuclear policy review."

The official added that the combined defense posture of South Korea and the US and the US' commitment to the provision of extended deterrence remain "solid."

Extended deterrence refers to the US' stated commitment to defending South Korea by mobilizing a full range of its military capabilities, nuclear and conventional, against North Korea's aggression.

The credibility of such extended deterrence has been called into question amid concerns that the North's push to develop intercontinental ballistic missiles and other military capabilities could keep American forces at bay in a contingency on the Korean Peninsula. (Yonhap)