North Korea says leader Kim Jong Un has warned again that he could use nuclear weapons in potential conflicts with South Korea and the United States, as he accused them of raising animosities on the Korean Peninsula. State media said Tuesday that Kim made such a warning in his speech at a university. Kim has issued similar threats to use nuclear weapons preemptively numerous times, but his latest warning came as outside experts say North Korea could ramp up animosities ahead of next month’s U.S. presidential election.