A mystery woman who has accompanied North Korea's new leader Kim Jong-Un to recent public events appears to be his wife, South Korea's top official on cross-border affairs said Wednesday.

Unification Minister Yu Woo-Ik said that "in my judgement she appears to be his wife", in response to a question from a lawmaker on parliament's foreign affairs committee. He did not say why he had reached that conclusion.

Kim Jong-Un, in his late 20s, took over as leader of the reclusive state from his father Kim Jong-Il who died in December, but little is known about the young leader.

A smartly dressed woman in her 20s or early 30s has been seen with Jong-Un at public events, and speculation has swirled about her identity.

Some analysts have previously suggested she might be Jong-Un's younger sister, although North Korean official media has not said who she is.

The short-haired brunette was first shown with Jong-Un during a concert in Pyongyang on July 5, wearing a yellow polka-dot dress and chic white jacket.

She was seen walking next to the leader on July 8 when he visited the mausoleum of his grandfather Kim Il-Sung.

On July 24, photos aired by state television showed the woman standing close to the new leader during a visit to a kindergarten.

With other officials staying a few steps behind the pair, the woman was seen grinning while standing immediately behind or next to Jong-Un as he hugged and talked to children.