Cuban state television has shown photos of a pajama-clad Fidel Castro chatting animatedly with an Argentine congressman, raising expectations that the ailing Cuban president will use the Nonaligned Movement summit to make his first public appearance since undergoing surgery in July.

National Assembly President Ricardo Alarcon said Wednesday that Castro "is doing well" and may participate in any activity at the Havana summit.

Castro, 80, has said he would have one-on-one meetings with foreign dignitaries. He was almost certain to meet with his close friend Venezuelan President Hugo Chavez, whom he has met three times since announcing on July 31 that he had undergone intestinal surgery and was temporarily ceding power to his 75-year-old brother, Defense Minister Raul Castro.

Bolivian President Evo Morales arrived early Thursday, the first of an array of U.S. critics whose appearances were highly anticipated.

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The summit comes just before a U.N. General Assembly session where Iran's nuclear ambitions and Venezuela's efforts to join the Security Council were to be discussed.

It has provided a fresh look at the collective leadership that has emerged during Castro's recovery. Raul has taken on his brother's protocol role, meeting with the leaders of Malaysia, Algeria and Vietnam, while several other top Cuban officials have given forceful speeches.

State television on Wednesday evening showed Castro sitting with Argentine Congressman Miguel Bonasso at a small table. The news program "Mesa Redonda" said Bonasso, a frequent visitor to Cuba, had come as a personal representative of Argentine President Nestor Kirchner.

Former President Carlos Menem, a close U.S. ally, pulled Argentina out of the Nonaligned Movement in the early 1990s, saying his country was no longer a Third World nation. The country has since been humbled by a peso crash and subsequent economic crisis. Cuba said Argentina is welcome to rejoin the movement.

One country that won't take part in the summit is the United States, which declined an invitation to attend as an observer. A press officer at the U.S. Interests Section in Havana said there would be no comment on any matters discussed at the summit.

Still, the policies of President Bush came up repeatedly. Alarcon gave a lengthy speech Wednesday accusing the U.S. of breaking its own pledge to fight terrorism by harboring Luis Posada Carriles, a former CIA operative and militant Castro foe wanted in Venezuela for the 1976 bombing of a Cuban airliner that killed 73 people.

On Monday, a federal magistrate in Texas said Posada Carriles should be released while he waits to be deported to any country but Cuba or Venezuela, where the U.S. fears he could be tortured.

"George W. Bush has said it, the White House said it: 'States that harbor terrorists are as guilty as the terrorists,"' Alarcon said. "Then I ask, 'Why does a federal judge decide that Posada Carriles can be set free?"'

Cuba, which takes over the group's three-year chairmanship from Malaysia on Friday, is trying to increase its prestige as a voice for the developing world.

Now including about two-thirds of the world's nations, the Nonaligned Movement developed during the Cold War as an alternative in a world split between the United States and Soviet Union. The movement grows to 118 members this week with the addition of the Caribbean states of Haiti and St. Kitts.

U.N. Secretary-General Kofi Annan will attend as an observer, and was expected to meet with Fidel Castro. Many of the global leaders are to continue on to the U.N. session in New York, and some plan to meet Bush in Washington.

Among other well-known leaders attending are presidents Mahmoud Ahmadinejad of Iran, Pervez Musharraf of Pakistan and Thabo Mbeki of South Africa, as well as prime ministers Manmohan Singh of India and Thaksin Shinawatra of Thailand. North Korea said it was sending its No. 2 leader, parliament head Kim Yong Nam.