China, Russia suffer wars, resolved to peace: Fidel Castro

China and Russia, with firsthand experience in ravages of wars fought on their soil, are resolved to find peaceful solutions to regional and global conflicts, former Cuban leader Fidel Castro has said.

"China and Russia know the world's problems much better than the US, because they were obliged to endure the terrible wars imposed on them by fascism," Xinhua quoted Castro as saying on Friday in his letter to Venezuelan President Nicolas Maduro.

"I do not doubt that, given their historical traditions and their own revolutionary experience, they will make the greatest effort to avoid a war and contribute to the peaceful development of Venezuela, Latin America, Asia and Africa," Castro said.

The retired Cuban leader, 89, also commented on the general state of insecurity worldwide, and the US' history of launching military interventions abroad, with devastating consequences.

"Security does not exist today for anyone," said Castro, noting "nine states possess nuclear weapons, including the US."

After bitter rivalry lasting over half a century, the US and Cuba restored their diplomatic ties on July 20, 2015. The two countries later re-opened their embassies in each other's capitals.

However, despite the lull in tensions, Washington continues to maintain a trade embargo on Cuba mandated by the US Congress.

Before ties are fully normalised, Havana demanded the end of the blockade, a return of the territory occupied by the US naval base in Guantanamo, and compensation for the costs caused by decades of economic sanctions.