UNITED NATIONS, Sept. 25 (Xinhua) -- U.S. President George W. Bush called on Tuesday for support from the international community to promote the process of democracy in some countries and to do necessary reform in the UN system.

    Addressing the UN General Assembly, Bush trumpeted democracy and freedom worldwide while announcing to impose new sanctions against Myanmar because of its alleged poor human rights record.

    "The United States will tighten economic sanctions on the leaders of the regime and their financial backers, and we will impose an expanded visa ban on those responsible for the most egregious violations of human rights as well as their family members," Bush said in a speech to the UN General Assembly.

    Bush also demanded the United Nations and its member states to use their diplomatic and economic leverage to force Myanmar to carry out political reform.

    The United States and Myanmar have been in a tense relationship over human rights issues.

    Accusing Myanmar's government of imposing political repression, Washington has been demanding the release of opposition leader Aung San Suu Kyi and thousands of political prisoners in Myanmar.

    Myanmar, which categorically rejects the U.S. accusations, insists that there is no political prisoners in the country.

    On Cuba, Bush urged the Central American country to have "free and competitive elections," claiming "in Cuba, the long rule of a cruel dictator is nearing its end."

    Noting that Cuba enters a period of transition and the Cuban people are ready for their freedom, Bush said "the United Nations must insist on free speech, free assembly and ultimately free and competitive elections."

    In protest against Bush's speech, the Cuban delegation stormed out of the plenary meeting of the UN General Assembly.

    The Cuban mission to the United Nations said in a statement that "Bush is responsible for the murder of over 600,000 civilians in Iraq, he authorized the torture of prisoners at the Guantanamo Naval Base and the kidnapping of people, as well as clandestine flights and secret prisons."

    "He is a criminal and has no moral authority or credibility to judge any other country," the statement said.

    The United States does not have full diplomatic relations with Cuba, and has maintained an economic embargo on the country for decades.

    Fidel Castro, who has been in power since 1959, underwent an intestinal operation in July 2006 and later handed over power to Cuban Defense Minister Raul Castro.

    Speaking of UN reform, the U.S. president said that "the United Nations must reform its own Human Rights Council."

    "The American people are disappointed by the failures of the Human Rights Council," he said, criticizing the newly-established Human Rights Council for ignoring problems in countries like the Democratic People's Republic of Korea and Iran while focusing its criticism excessively on Israel.

    "To be credible on human rights in the world, the United Nations must first reform its own Human Rights Council," Bush said.

    The UN Human Rights Council, successor to the UN Commission on Human Rights, was established by the UN General Assembly on March 15, 2006.

    The United States opposes the establishment of the organization from the very beginning.

    On the issue of expanding the Security Council, the UN's most powerful body, Bush suggested that Japan is "well qualified" to bean additional member and said "other nations should be considered as well."

    "The United States will listen to all good ideas, and we will support changes to the Security Council as part of broader UN reform," he added.