"Old friend" is a common phrase China’s communist party uses as a tribute to foreigners considered helpful to their interests. It’s also an expression of nostalgia for longtime companions or acquaintances.
Is this real or did they just made it up to make China sound more mysterious and different lol
States/provinces within a federation usually have sister relationships with equivalent gubernatorial bodies, so for example Iowa is sister states with Hebei province while Des Moines is sister cities with Hebei's Shijiazhuang.
(Sister citites don't always have to be from the sister state, though in this case they align)
Xi came out to the USA on an agricultural delegation from Hebei.