World leaders attending this week's Nuclear Security Summit in Seoul are planning a string of high-profile bilateral talks on the sidelines of their discussions on preventing nuclear-armed terror.

Participating leaders from 53 nations and four international organizations will have held approximately 250 bilateral summit meetings by Tuesday, according to the event's Preparatory Secretariat.

U.S. President Barack Obama, who arrived in Seoul on Sunday, began his second-day schedule with a special lecture emphasizing the role of South Korea in the international community at Seoul's Hankuk University of Foreign Studies, the Web site of the secretariat said.

Analysts say his visit to the university, which is the first time for a U.S. president to do so, reflects his admiration for the South's education system.

Later in the day, Obama is scheduled to hold bilateral talks with Russian President Dmitry Medvedev and Chinese President Hu Jintao, both of whom are in Seoul for the two-day nuclear summit. 

After the U.S.-China talks, Hu will hold a summit meeting with South African President Jacob Zuma to discuss current state of affairs in Africa.

Medvedev is scheduled to hold summit talks with Spanish Prime Minister Mariano Rajoy Brey as well as King Abdullah II of Jordan.

The U.S., Chinese and Russian leaders will all have held bilateral summit talks with South Korean President Lee Myung-bak in Seoul by the end of the summit.

China and Russia do not have plans to hold one-on-one talks during the summit, according to the Web site.

Thai Prime Minister Yingluck Shinawatra, who arrived in Seoul Saturday, will give a special lecture at Ewha Womans University Monday and attend a luncheon hosted by South Korea's business organizations later in the day. (Yonhap News)