FILE - In this June 12, 2018, file photo, North Korea leader Kim Jong Un, left, and U.S. President Donald Trump shake hands at the conclusion of their meetings at the Capella resort on Sentosa Island in Singapore. To hear a beaming Donald Trump at his June summit with Kim Jong Un in Singapore, the solution to North Korea’s headlong pursuit of nuclear weapons, a foreign policy nightmare that has flummoxed U.S. leaders since the early 1990s, was at hand. (AP Photo/Susan Walsh, Pool, Fie)

Clashing views color future of stalled N.Korea nuclear talks

So even as Trump says he's keen on another summit, continuing U.S. sanctions and pressure are met with anger and foot-dragging from Pyongyang, which has bluntly stated that an improvement of relations and sanctions are incompatible.

One of the problems is a matter of wording. The July statement calling for "the complete denuclearization" was so vague that it seemed tailor made for a stalemate: Each side can claim to be right when they say that they've done more than enough and it's the other side's responsibility to act.