Iran's President Mahmoud Ahmadinejad slammed capitalism as bankrupt and called for a new world order Wednesday on a visit to Cuba, steering clear of the controversy over his country's nuclear program. The Iranian leader arrived in Cuba for talks with his counterpart Raul Castro as the Islamic republic blamed Israel and the United States for the killing of a nuclear scientist in a Tehran car bombing. The scientist's killing heightened already high tensions with the West over Iran's suspect nuclear program, but a defiant Ahmadinejad flashed the victory sign several times after landing in Havana. The Iranian leader was greeted by nine girls in traditional Iranian attire as he stepped off the plane that flew him in from Nicaragua on the third leg of his Latin American tour, aimed at shoring up ties in the region. Ahmadinejad was taken to the University of Havana where he picked up an honorary doctorate and told students in the Americas' only Communist country that capitalism could soon be on its last legs. "Our shared task, mission and challenge is to make a great effort for justice to be achieved, (otherwise) millions will suffer injustice," Ahmadinejad said. "We are watching the capitalist system decay... it is heading toward a dead end," he said, stressing that what is needed is "a new order, a fresh look, that respects all human beings, a way of thinking that is based on justice." Ahmadinejad repeatedly took swipes at the United States but did not address the rising tensions over Tehran's nuclear program, which the West says is aimed at developing weapons -- a charge Iran denies. "Today the only thing capitalism does is kill. It is a failed system in decay," he said. Ahmadinejad's arrival came hours after Mostafa Ahmadi Roshan, a 32-year-old nuclear scientist, was killed in Tehran. Iran pointed the finger at Israel and the United States, which have vowed to prevent Iran from building a nuclear weapon. Iran's Vice President Mohammad Reza Rahimi told state television the killing, which occurred in front of a university campus in east Tehran, would not stop Iran making "progress" in its nuclear activities. Iranian officials said the assassination method -- two men on a motorbike attaching a magnetic bomb to the target's vehicle -- was similar to that used in the killings of three other "The United States had absolutely nothing to do with this. We strongly condemn all acts of violence, including acts of violence like this," said National Security Council spokesman Tommy Vietor. The killing came after confirmation by the UN nuclear watchdog IAEA that Iran had begun enriching uranium in a new, underground bunker, a development that the United States, Britain, France and Germany denounced as an unacceptable violation of UN Security Council resolutions. Faced with growing pressure from the West, Ahmadinejad has been seeking support from four Latin American countries hostile to Washington. Cuba and Iran share similar positions in international organizations, with Tehran condemning the half-century US trade embargo against Cuba and Havana recognizing Iran's right to develop nuclear energy for peaceful purposes. Israel, Tehran's sworn enemy, has threatened to launch air strikes on Iran's nuclear facilities. The United States has said "all options are on the table" in terms of dealing with Iran -- including military action. Tehran has meanwhile threatened to close the strategic Strait of Hormuz at the entrance to the Gulf if it is attacked. Twenty percent of the world's tanker-carried oil flows through the strait.