Xi was writing in Serbian daily Politika ahead of arriving in the Serbian capital Belgrade later on Tuesday, the next stop on his first visit to Europe since the Covid pandemic.

His visit coincides with the 25th anniversary of the bombing by the military alliance, which was blamed on a CIA mapping error that left three dead.

"Twenty-five years ago today, NATO flagrantly bombed the Chinese embassy in Yugoslavia, killing three Chinese journalists," Xi wrote in Politika.

"This we should never forget. The Chinese people cherish peace but we will never allow such tragic history to repeat itself."

He also hailed the "iron-clad friendship" between China and Serbia, which he said was "forged with the blood of our compatriots".

Xi is expected to arrived in Belgrade on Tuesday night after a state visit to France which saw sometimes robust exchanges with President Emmanuel Macron on topics including the Ukraine war.

His next two European stops -- Serbia and Hungary -- are seen as among the most sympathetic in Europe to Moscow, which invaded Ukraine in February 2022.

China has poured billions into Serbia and neighbouring Balkan countries, particularly into mining and manufacturing, and last year Beijing and Belgrade signed a free trade agreement.