More than 30 of the global leaders attending next week's nuclear summit in Seoul are expected to arrive in private planes, putting airport authorities on high alert for the extra traffic they will generate, officials said Thursday.

A total of 58 leaders and ranking officials from 53 nations and four international organizations are expected to attend the March 26-27 Nuclear Security Summit in Seoul to discuss safeguards against the use of nuclear materials by terrorist groups, among other issues.

U.S. President Barack Obama, Chinese President Hu Jintao, Russian President Dmitry Medvedev and U.N. Secretary-General Ban Ki-moon are among the 39 heads of state or global organizations scheduled to take part, according to the event's Preparatory Secretariat.

More than half, or 32, of the participating leaders and ranking officials are due to arrive in private planes, accompanied by 12 cargo and reserve aircraft, officials at the secretariat said. They will mostly land between Sunday and Monday at three main airports in the capital area, including Incheon International Airport, along with the other participants who will travel on commercial flights, the officials said.

Airport authorities plan to operate a 24-hour situation room and bring additional equipment from regional airports to ensure smooth logistical support, while the foreign ministry will concentrate on the protocol of receiving foreign guests, they added.

The government said earlier it will raise security levels at key airports to "red" during the March 23-27 period, the highest level on a five-tier alert system. It also said inspection personnel will redouble screenings of all passengers, baggage and cargo to prevent terrorist activities. (Yonhap News)