(REUTERS) - Former Cuban leader Fidel Castro spoke on Tuesday (April 19) at what he said could possibly be his last address to Congress before signaling his approval of candidates during the country's first congressional meeting since 2011.

"Soon, I will be turning 90 years old. I never imagined it and it has not been the fruit of any labor it was purely a whim by destiny," Mr Castro said.

"This could possibly be one of the last times that I speak from this room. I have voted for all of the candidates who have been submitted by Congress and I am thankful for the invitation and the honour of you all listening to me. I congratulate everyone but firstly, comrade Raul Castro for his magnificent efforts," he said.

Mr Castro finished: "We will start the march and we will perfect that which we have to perfect with unwavering loyalty and united strength, like (Jose) Marti, (Antonio) Maceo and (Maximo) Gomez, we will march unstoppably. (The) End."

The Communist Party, whose leadership elections were announced by state media on Tuesday, wants avoid any chaotic collapse as it wrestles with economic change and a transition from the generation of leaders who fought in the 1959 revolution.

At the end of the congress, the Communist Party said Mr Raul Castro had been re-elected as first secretary, with Mr Jose Ramon Machado Ventura, 85, re-elected as second secretary.