It means that Trump has public meetings in Japan and non-public meetings with China and South Korea.
Trump has public meetings in Japan.
And non-public meetings with China and South Korea, while in Japan.
You don't have to visit China and South Korea.
Trump is presumably meeting with officials from China and South Korea in Japan.
"Follow the pen" means that everytime
Q posts the black pen, new executive orders
were signed.
It means: new executive orders will soon be made public.
I'm sure Trump will give Japan a peace treaty soon.