President Barack Obama used his first visit to the demilitarized zone that splits the Korean peninsula to peer through binoculars into North Korea where flags flew at half-staff to mark the 100-day anniversary of the death of Kim Jong Il.

The stop at the border Sunday marked the start of a three-day trip to South Korea where the American president is to attend an international nuclear summit.

Top officials from 54 countries including China and Russia will attend the summit. President Obama looked through binoculars toward North Korea from Observation Post Ouellette while touring the demilitarized zone on the border between North and South Korea