Leaders and other senior officials from more than 100 nations are scheduled to meet Friday and Saturday in Havana, Cuba, for for the annual summit of the Non-Aligned Movement.
United Nations Secretary-General Kofi Annan is due to address the gathering Friday. Iran's President Mahmoud Ahmadinejad and Venezuelan President Hugo Chavez are among those attending.
Iran's nuclear program and Venezuela's bid for a seat on the U.N. Security Council are likely items topping the summit's agenda.
The Non-Aligned Movement now has 116 members. It was formed more than four decades ago with the aim of avoiding alignment with the United States or the Soviet Union during the Cold War.
It is not clear whether Cuban President Fidel Castro will participate in the meeting.
The 80-year-old Mr. Castro has not been seen in public since he underwent intestinal surgery and temporarily transferred power to his younger brother, Defense Minister Raul Castro, in July.
However, Cuban television has shown video of Mr. Castro during his recuperation, including a private meeting Thursday with political ally and friend, Venezuelan President Hugo Chavez. There also were television pictures of Mr. Castro meeting with U.N. Secretary-General Kofi Annan.
Mr. Chavez said Mr. Castro was "walking and singing," and he joked that the Cuban leader is doing so well he is almost ready to play baseball. Both men are avid baseball fans.
Some information for this report was provided by AFP.