SINGAPORE, November 14 (RIA Novosti) - U.S. President Barack Obama has arrived to the summit of Pacific Rim countries in Singapore on Saturday.

Leaders from 21 countries are currently attending the annual Asia-Pacific Economic Cooperation (APEC) summit.

Obama arrived one day later to the summit than his other counterparts because he was attending a mourning ceremony for the victims of the Fort Hood military base shooting in Texas.

Maj. Hasan, 39, an Army psychiatrist who reportedly was upset about his upcoming deployment to Afghanistan, is suspected of going on a shooting rampage at the Fort Hood military base in Texas, killing 13 people and wounding dozens of others on November 5.

Obama will meet with Russian President Dmitry Medvedev on Sunday during a sideline meeting to discuss a new arms reduction deal and the Iranian and North Korean nuclear programs, a Russian presidential aide said on Friday.