The United Nations (search) must make itself more relevant to tackle 21st century problems and should condemn as terrorists those who target civilians whatever their cause, Secretary of State Condoleezza Rice (search) said Saturday.

Recalling the historic founding of the United Nations 60 years ago, Rice told the General Assembly, "In this new world, we must again embrace the challenge of building for the future."

World leaders at a summit this week adopted a watered-down version of proposed reforms advanced by Secretary-General Kofi Annan (search) and by the Bush administration.

Rice, in her first speech before the General Assembly, called on the 191 nations to try harder.

"The time to reform the United Nations is now," she said. "And we must seize this opportunity together."

Rice placed terrorism at the head of her list. Appealing for adoption of a comprehensive convention on terrorism, she said there could be no definition of terrorism that excludes from condemnation any group that harms innocent civilians.

Defying the view that one man's terrorist is another's freedom fighter, Rice said, "No cause, no movement, and no grievance can justify the intentional killing of innocent civilians and noncombatants."

She added, "This is unacceptable by any moral standard."

Preceding Rice to the rostrum, Annan said condemnation of terrorism must be unqualified and that the 191 countries should "forge a global counterterrorism strategy that weakens terrorists and strengthens the international community."

In her speech, which drew modest applause, Rice called on rich countries to help poor ones with development assistance. And developing countries, she said, "have responsibility to govern justly, to advance economic liberty, and to invest in their people."

The reform document adopted this week makes a stab at revising the way the United Nations deals with human rights. Rice called for a much tougher approach.

She said the new council that is being established should have more credibility. And that, she said, means it should "never, never empower brutal dictatorships to sit in judgment of responsible democracies."

The council, Rice said, "must have the moral authority to condemn all violators of human rights — even those that sit among us in this hall."

"For this institution to become an engine of change in the 21st century it must now change itself," Rice said. "The United Nations must launch a lasting revolution of reform."

Rice has locked arms with Annan on reform, declaring him an effective manager with whom she can work closely.

"I have never had a better relationship with anyone than Kofi Annan," Rice said this week, thereby separating U.S. concerns about management flaws and corruption from the world body's top diplomat.

In her speech, Rice dealt with the 35-page reform document as a useful first step, but no more than that.

The U.S. delegation, headed by reform-minded Ambassador John R. Bolton (search), never reluctant to point out U.N. shortcomings even at the risk of irritating traditional diplomats, is expected to follow up Rice's recommendations with resolutions in the coming weeks.

President Bush, in his speech this week to the U.N., tried to motivate adoption of measures to counter poverty by linking poverty with terrorism. He listed a number of countries that have suffered at the hands of terrorists.

While reform was the centerpiece of her speech, Rice also dealt with world trouble spots, especially Iran and its refusal to negotiate with the European Union (search) an end to activities that suggest it is developing nuclear weapons.

"Questions about Iran's nuclear activities remain unanswered, despite repeated efforts" by the U.N. nuclear watchdog agency, she said. But she deleted from her prepared speech a reference to Iran as a leading supporter of terrorism.

Rice already has backed away from an immediate showdown with Iran in the Security Council, where censure or sanctions might not be able to win approval. China, Russia and India, targets of a public U.S. campaign, have all indicated they are not inclined to move against Iran.

Iran, meanwhile, has challenged the administration to produce evidence that it is in violation of international standards in its nuclear activities. President Mahmoud Ahmadinejad (search) planned to rebut the U.S. position in his own speech Saturday.