A South Korean unification activist on an unauthorized visit to North Korea met with the communist nation's No. 2 leader on Wednesday, Pyongyang's official news agency reported.

Ro Su-hui, 68, a leader of a pro-Pyongyang organization, has been in North Korea since March 24 on an unsanctioned trip to attend a memorial service to mark the 100th day anniversary of the death of Pyongyang's long-time leader Kim Jong-il.

He is scheduled to return to the South through the border village of Panmunjom on Thursday.

On the eve of his return, Ro met with Kim Yong-nam, the North's ceremonial head of state considered second in line to leader Kim Jong-un, "in a compatriotic atmosphere," the North's official Korean Central News Agency said in a brief dispatch.

Police in South Korea say they will arrest Ro at the border village for questioning about his pro-North Korean activities in the North. He could face up to 10 years in prison if convicted of sneaking into the North, according to police.

North Korea has warned the South against arresting Ro.

Seoul's anti-communist National Security Law prohibits citizens from visiting the North without prior approval or from praising the North.

(Yonhap News)