ISTANBUL (AFP/Reuters) - Iranian President Mahmoud Ahmadinejad Monday slammed capitalism for the global financial meltdown as he joined Muslim leaders at a summit in Turkey amid increasing pressure on his country over its nuclear drive. The present economic crisis is due to the capitalist system. The world needs radical change, Ahmadinejad told a one-day economic summit of the Organisation of the Islamic Conference (OIC). Describing interest rates as the biggest and most fundamental problem of the capitalist system, the Iranian leader said through a translator: The world system based on usury has collapsed, proving its failure. We have to draw up programmes based on Islamic economic thinkers. That way we can guide people to happiness, security, justice and honesty, he told participating leaders, including Syrian President Bashar Al-Assad and Afghan President Hamid Karzai. Ahmadinejad made no reference to Tehrans dispute with the West over its nuclear activities, but his presence in Istanbul coincides with international pressure on Iran to agree to a UN-brokered plan to provide Iran with enriched uranium for a Tehran reactor. Under the proposals thrashed out in talks with France, Russia and the United States, Iran would ship most of its own stocks of low-enriched uranium abroad in return for fuel to power a research reactor in Tehran. The proposals were designed to assuage fears that Iran could divert some of its uranium and further enrich it to reach the higher levels of purity required to make an atomic bomb. Turkish President Abdullah Gul, whose country is nurturing closer ties with neighbouring Iran, expressed hope for concrete and positive results on the proposal package and said Ankara was ready to help. Turkey will continue to strongly support the process to find a diplomatic solution to this issue and play a facilitative role, he said in his opening remarks. Afghan President Hamid Karzai appealed for closer trade ties with fellow Muslim countries to help Afghanistan break its cycle of conflict. Karzai met representatives of eight governments, including Turkish President Abdullah Gul and Iranian President Mahmoud Ahmadinejad, on the sidelines of an economic summit held by the Organisation of the Islamic Conference in Istanbul. Afghanistans interest is primarily in having close brotherly relations with its neighbours, freedom of trade and transit, and an effective environment of cooperation, he told a breakfast meeting before the formal opening of the summit. A Turkish Foreign Ministry official said there would be a follow-up conference on Afghanistan in the near future, which Turkey had offered to host. Turkey has troops serving with Nato forces in Afghanistan and Gul sought to rally support for the mission to stabilise Afghanistan and eradicate groups such as al Qaeda. We are there to stop the threat of terrorism to the entire region and the world, Gul said. As stakeholders in the region, we cannot expect that the US and other Western powers solve the problems by themselves. We should shoulder our responsibilities, Gul said. The Turkish president expressed support for Karzais efforts to unite the country after the bitterly fought election. I am confident that the focus in the short term will be on the establishment as soon as possible of a government that would pull the country back together and embrace every corner of Afghanistan and every segment of Afghan society. This is urgently needed after a long election process.