SK announced it won't ne-negotiate KORUS. Trump called it unacceptable. So KORUS is dead. 

The THAAD is a high-attitude medium range anti-missile system, which when tuned to a lower attitude become long range. It is IMPOSED by the Pentagon on SK directed against China. It is overkill for NK lousy primitive missiles. If SK wants THAAD it would ask for it but it does not. In fact there are very strong oppositions. You would think SK would care more about its defense than America. SK have announced it will not pay for THAAD, and that the next president will decide on permit to install. 

SK is against the U.S. trying to start a war on NK using nuke a pretax. Only the American generals are beating the war drums, because they always need war. Cold War 2 on the Russian front is getting cold and the Pentagon want to start a new front. 

You know, I get the feeling SK has just about had it with Trump and the American War Machine. So is Japan. Maybe this is why Tokyo is talking to Moscow.