Kim Jong Un speaks English, likes basketball - and is said to look and act just like his father. The reclusive, nuclear-armed communist nation's next leader has been the focus of intense media speculation since Mr Kim, 67, reportedly suffered a stroke last summer.

Mr Kim has ruled with absolute authority since his father, Kim Il Sung, died in 1994, leading to the communist world's first hereditary power succession.

Kim Jong Il has allowed no opposition, raising concerns about a power struggle if he dies suddenly without naming a successor.

The eccentric leader has three known sons by two women. The oldest, Kim Jong Nam, was long considered his favourite - until he tried to sneak into Japan using a fake Dominican passport and visit Tokyo's Disney resort in 2001.

The middle son, Kim Jong Chol, apparently has never been a favourite as a possible leader. But talk about the youngest son has been growing. On Sunday, South Korea's Yonhap news agency reported Kim Jong Un was assigned to a low-level post at the defence commission, the top government body, several days before his father was reappointed as the commission's chairman on April 9.

Yonhap, citing unidentified sources it says are privy to North Korea affairs, said Kim Jong Un's appointment means he has embarked on his training as successor and is expected to move step by step into the commission's higher-level posts.

The teen studied at the International School of Bern in Switzerland, a short walk from the North Korean embassy, where classes are taught in English and many students come from diplomatic families.

Cheong Seong-chang, a senior analyst at the security think tank Sejong Institute said Kim Jong Il's health problems would speed up his naming an heir.

But Yang Moo-jin, a professor at the University of North Korean Studies, disagreed, saying Kim Jong Il is believed to be focusing more on consolidating his support base rather than appointing his successor, which would quickly erode his power and 'worsen his health condition'. -- AP