SEOUL, South Korea (AP) — North Korean leader Kim Jong Un is to tour a Russian aircraft plant that builds fighter jets and then visit the country’s Pacific Fleet, but his exact whereabouts remain uncertain, as South Korea on Thursday expressed “deep concern and regret” that his visit has focused so far on expanding military cooperation. Washington has warned that the summit on Wednesday between Kim and Russian President Vladimir Putin could lead to a deal for North Korea to supply ammunition for Moscow’s war in Ukraine. There’s widespread concern in Seoul that North Korea in return would receive advanced weapons technologies from Russia, including those related to military spy satellites, which would increase the threat posed by Kim’s military nuclear program.