The nuclear summit between President Donald Trump and North Korea’s Kim Jong Un collapsed Thursday after the two sides failed to reach a deal due to a standoff over U.S. sanctions on the reclusive nation, a dispiriting end to high-stakes meetings meant to disarm a global threat. Trump, in a news conference after the summit abruptly shut down early, blamed...

U.S. President Donald Trump and North Korea’s Kim Jong Un, leaders of two nations with a long history of hostilities, opened their second summit Wednesday with smiles, hopeful talk and a friendly dinner that will set the stage for more difficult talks to come about curbing North Korea’s pursuit of nuclear weapons. Facing widespread skepticism about what they can achieve,...