Venezuelan President Hugo Chavez took his verbal battle with the United States to the floor of the UN General Assembly on Wednesday, calling US President George W. Bush "the devil" and denouncing what he said was US imperialism. The impassioned speech by Chavez, a leftist and one of the Bush's staunchest critics, came a day after the US president and Iranian President Mahmoud Ahmadinejad sparred over Tehran's disputed nuclear program but managed to avoid a personal encounter. "The devil came here yesterday," Chavez said, referring to Bush's address on Tuesday and making the sign of the cross. "He came here talking as if he were the owner of the world." Standing at the podium, Chavez quipped that a day after Bush's appearance: "In this very spot it smells like sulfur still." Chavez held up a book by American leftist writer Noam Chomsky "Hegemony or Survival: America's Quest for Global Dominance" and recommended it to everyone in the General Assembly. The leftist leader, who has joined Iran and Cuba in opposing US influence, accused Washington of "domination, exploitation and pillage of peoples of the world." "We appeal to the people of the United States and the world to halt this threat, which is like a sword hanging over our head," he said. Chavez's diatribe reflected the difficulty Bush faces in his key mission at the UN - convincing a largely skeptical world audience that his administration's fight against terrorism was not one targeting Muslims. The main US seat in the assembly hall was empty as Chavez spoke. But there was a "junior note taker" there, as is customary "when governments like that speak," the US ambassador to the UN said. Ambassador John Bolton told The Associated Press that Chavez had the right to express his opinion, adding it was "too bad the people of Venezuela don't have free speech." "I'm just not going to comment on this because his remarks just don't warrant a response," Bolton said. "Serious people can listen to what he had to say and if they do they will reject it." Describing the UN as an "important world stage" on which leaders represent their citizens, State Department deputy spokesman Tom Casey, said such personal attacks were "disappointing." "You know, the UN is an important world stage, and an important forum, and leaders come there representing their people and their country," Casey said in Washington. "And I'll leave it to the Venezuelan people to determine whether President Chavez represented them and presented them in a way they would have liked to have seen." Chavez drew tentative giggles at times from the audience, but also some applause when he called Bush the devil. Chavez also urged Pope Benedict XVI to be more careful with his words, saying he found the pontiff's recent remarks regarding Islam and holy war "worrisome." "I think the Vatican should clarify the position much better because I believe many doubts still linger among our Muslim brothers of the world," Chavez told Venezuelan state-run television. "We see the pope's words with worry." "Those who have so much weight with the word (shouldn't be) saying something that could be misinterpreted and throw more fuel on the fire," added the Venezuelan president. The Mideast peace process also was in the spotlight at the UN General Assembly, with ministers from the Quartet that drafted the stalled road map - the US, the UN, the European Union and Russia - planning to meet. The Security Council also was scheduled to hold a ministerial meeting Thursday that Arab leaders hope will help revive the Mideast peace process. Ahmadinejad took the podium hours later, denouncing US policies in Iraq and Lebanon and accusing Washington of abusing its power in the Security Council to punish others while protecting its own interests and allies. The hard-line leader insisted that his nation's nuclear activities were "transparent, peaceful and under the watchful eye" of inspectors from the International Atomic Energy Agency, the UN nuclear watchdog. He also reiterated his nation's commitment to the Nuclear Nonproliferation Treaty. Although the two leaders spoke from the same podium, they skipped each other's addresses and managed to avoid direct contact during the ministerial meeting. Also on Wednesday, Afghan President Hamid Karzai warned that terrorism is rebounding in his country and said efforts to build democracy there had suffered setbacks over the past year as violence increased, especially in the volatile south where NATO forces have been battling Taliban militants in some of the fiercest battles since the hard-line government was toppled in 2001. "We have seen terrorism rebounding as terrorists have infiltrated our borders to step up their murderous campaign against our people," he told the General Assembly. He said the situation was so bad it had contributed to a rise in polio from four cases in 2005 to 27 this year because health workers were unable to reach the region. But he said the problem had to be fought beyond Afghanistan's borders as well as within. "We must look beyond Afghanistan to the sources of terrorism," he said. "We must destroy terrorist sanctuaries beyond Afghanistan." He also expressed concern about "the increased incidents of Islamophobia in the West," saying it does not "bode well for the cause of building understanding and cooperation across civilizations." The crisis in the ravaged Sudanese region of Darfur also was on the agenda Wednesday, with the African Union's Peace and Security Council meeting to discuss breaking the deadlock over a plan to replace an AU force with UN peacekeepers. The bloc decided to extend the mandate of peacekeeping forces in Darfur through the end of the year, ensuring that international troops will remain in the war-torn Sudanese province for now. The United Nations will provide material and logistic support to the mission, though Sudan is still resisting demands that the UN take over the mission from the AU, said Burkina Faso President Blaise Compaore, head of the AU Peace and Security Council.