The peoples of the two countries have long shared a deep and lasting bond.
Tips
register
Formal, warm. Typical in toasts, diplomatic statements, farewell speeches, and thank-you notes. Too ceremonious for casual friendship talk - use 真挚的友情 or simply 感情很深 in everyday speech.
memory
深 (deep) + 情 (feelings) + 厚 (thick) + 谊 (friendship). Two depth-adjectives on two emotion-nouns - friendship both deep and thick, a doubled-up bond.
