Cuba's communist model needs "urgent changes" to overcome a major crisis which cannot be blamed solely on a crippling US oil blockade, President Miguel Díaz-Canel said in his frankest admission yet of the need for radical reforms.

While Havana's impulse has been to blame its problems on a more-than-six-decade US trade embargo and more recent blockade, Díaz-Canel admitted in remarks broadcast on Thursday there were "obstacles that don't come from outside, nor the blockade."

He called out "slowness, bureaucracy and norms that impede those who want to produce" as well as "decisions that we have put off" for contributing to the worst crisis in living memory.

"The situation calls for urgent and necessary changes," he told the Communist Party Central Committee.

Díaz-Canel was speaking at a party meeting convened hastily to fast-track reforms aimed at boosting the private sector and attracting investment from millions of Cubans who have fled abroad.