Absent from the recent summit between the leaders of North and South Korea was Pyongyang's human rights record, and the issue appears to have faded from U.S. President Donald Trump's public agenda as he prepares for his own meeting with Kim Jong Un.

Rights activists and North Korean defectors fear that when Trump sits down with Kim, he may avoid the thorny issue of rights altogether if that helps seal a deal on getting North Korea to abandon nuclear weapons.

Just a few months ago, rights abuses were a focal point of Trump's criticism of North Korea, along with its pursuit of nuclear-armed missiles. Trump called Kim "obviously a madman who doesn't mind starving or killing his people".