SEOUL, April 25 -- U.S. President Barack Obama arrived here Friday afternoon to hold summit with his South Korean counterpart Park Geun-hye to discuss issues of the Democratic People's Republic of Korea (DPRK)'s nuclear program and the South Korea-U.S. alliance amid rising tensions in the region.

Obama began his four-nation Asian tour in Japan where he met with Japanese Prime Minister Shinzo Abe before arriving in South Korea for a two-day trip.

The U.S. president headed first for the War Memorial of Korea where he laid wreath in honor of American soldiers dead during the 1950-53 Korean War and mourned them.

Then, he moved to the Gyeongbok Palace that had been the main palace of Joseon Dynasty (1392-1901). Obama visited the palace as he reportedly wanted to conduct a cultural activity at the symbolic place of the country.

Obama arrived in the South Korean presidential office of Cheong Wa Dae for talks with Park. The two leaders will discuss situations on the Korean Peninsula, including the DPRK's nuclear program, situations in the Northeast Asia and how to advance South Korea-U.S. alliance.

Ju Chul-ki, senior foreign affairs and security advisor to Park, said Thursday that the upcoming summit will serve as an opportunity to solidify the South Korea-U.S. alliance amid the grave security situation on the Korean Peninsula and reaffirm watertight cooperation in response to what he called the DPRK's nuclear threats.