The President of the United States Joe Biden on Sunday said that his country and South Korea were prepared for "anything that South Korea does," amid indications that Pyongyang might be preparing for a fresh nuclear test or test-launching ballistic missiles soon.

Biden was answering questions during an event in Seoul on Sunday over the possibility of North Korean leader Kim Jong-un's regime carrying out a weapons test during the US president's ongoing South Korea visit.

"I am not concerned, if that is the question," Biden said during his media appearance at Seoul's Hotel Grand Hyatt, where he met Hyundai Motor group chairman Ching Eui-sun to discuss the South Korean carmaker's fresh investment plans in the US.