SEOUL, South Korea (AP) — North Korean leader Kim Jong Un is on his way home from Russia at the end of a six-day trip that triggered global concerns about weapons transfer deals between the two countries locked in separate standoffs with the West. Kim began his journey back to North Korea Sunday aboard his armored train from the Primorye region in Russia’s Far East, following a farewell ceremony at a train station, according to Russian media. Since entering Russia last Tuesday in his first overseas trip in more than four years, Kim had met President Vladimir Putin and visited key military and technology sites. Earlier Sunday, he was in a lighter mode, touring a university and watching a walrus show at a Russian aquarium.