There is confusion in Cuba over whether President Fidel Castro is to make his first public appearance this week after surgery for intestinal problems.
Fidel Castro recently underwent intestinal surgery
One official timetable says Mr Castro will host a dinner for the Non-Aligned Movement next Friday.
But Foreign Minister Felipe Perez Roque said he could not be certain that the 80-year-old leader would attend.
Mr Castro handed temporary power to his brother in July, prompting speculation that his 47-year rule was nearly over.
A Cuban statement last week said he was over the worst of his illness.
Details of the ailment have been a state secret, although photographs of Mr Castro meeting Venezuelan leader Hugo Chavez in hospital were released last month to quell fears that he had died.
He has met Mr Chavez three times since his surgery and also held a private meeting last week with Bolivian president Evo Morales.
A handwritten statement published in state newspaper Granma last week revealed that Mr Castro had lost more than 18kgs (40lbs) during the illness but was now getting better.
"One can say that the most critical moment is behind us. Today, I am recovering at a satisfactory pace," he wrote.
An official schedule of the Non-Aligned Movement meeting released on Sunday said that Mr Castro would attend a welcoming dinner for visiting leaders at 2030 local time on Friday (0030 GMT).
But the foreign minister said that that was not certain, adding that if Fidel Castro could not attend, his brother, acting president Raul Castro, would do so instead.
A statement earlier this week suggested that Mr Castro would hold several small and private fringe meetings with visiting leaders during the summit, although no details were given in Sunday's schedule.
Most observers believe that if he is healthy enough to appear in public in the next few days, he will.
Cuba is taking over chairmanship of the Non-Aligned Movement from Malaysia.
The grouping brings together leaders and dignitaries from 116 developing nations.
Among those attending the meeting are UN Secretary General Kofi Annan and Presidents Mahmoud Ahmadinejad of Iran, Pervez Musharraf of Pakistan, and Bashar Assad of Syria, as well as Prime Ministers Manmohan Singh of India and Thaksin Shinawatra of Thailand.