Clinton Calls for Continued U.S. Support of U.N. : Celebration: ‘We still need the United Nations’ to help solve problems, he tells Americans. Historic gathering of world leaders marks the organization’s 50th anniversary.

President Clinton, opening a glittering celebration of the United Nations’ 50th anniversary, told Americans on Sunday that they should support the often-scorned organization because it can help solve global problems of crime, terrorism and environmental damage that strike close to home.

“We still need the United Nations,” Clinton said in a speech to more than 180 world leaders, from Russian President Boris N. Yeltsin to Cuban President Fidel Castro and the chiefs of dozens of tiny island nations, gathered in the vast auditorium of the U.N. General Assembly in New York City.

“We can’t free our own neighborhoods from drug-related crime without the help of countries where the drugs are produced,” he said. “We can’t track down terrorists without assistance from other governments.”

At a time when the American public seems increasingly exasperated with the United Nations’ inability to solve such global crises as the war in Bosnia-Herzegovina, Clinton told the leaders that the world body deserves credit for half a century of peacemaking around the world, including in Bosnia.

But Clinton reserved his main point not for the assembled potentates but for the American voters.

The United States needs the world body not only to preserve peace, he asserted, but to help solve some domestic problems as well.

“As the Cold War gives way to the global village . . . progress can spread quickly, but trouble can too,” Clinton said, citing terrorism, organized crime and weapons proliferation as global problems. “Trouble on the far end of town soon becomes a plague on everyone’s house.”

To underscore his point, he unveiled a list of measures to fight global organized crime, including an executive order freezing U.S. financial dealings with four accused Colombian drug lords and a threat of sanctions against countries that allow money laundering to flourish.

Clinton also promised to pay the $1.4 billion in unpaid dues and peacekeeping costs the United States owes the United Nations--although aides acknowledged they have not yet figured out how to pry the money out of a balky Congress.

“I don’t think the United States wants to be known as the biggest deadbeat in the U.N. ,” the President told reporters later.

The United States is both the biggest contributor to the organization and its biggest debtor.

The anti-crime measures Clinton announced Sunday had little direct connection to the United Nations, which has also been working to step up international cooperation to fight drug kingpins and other trans-border malefactors.

But they served to illustrate Clinton’s political point--aimed at the audience outside--that even when he is visibly spending time on foreign policy, his heart is still in domestic problems.

The measures Clinton an nounced include:

* An executive order barring U.S. banks and other companies from dealing with four accused Colombian cocaine kingpins, 43 of their relatives and associates and 33 Colombian companies suspected of cocaine connections. The order also freezes any U.S. assets the Colombians may hold, although officials said they do not know whether the suspects have any bank accounts or other assets in this country.

“What we expect on the basis of this action is that we will be able to uncover the extent of the worth of these companies and deny them the benefits of normal trade with the United States,” said Robert S. Gelbard, assistant secretary of state for international narcotics matters.

* New threats of economic sanctions against countries that turn a blind eye to widespread money laundering by drug traffickers and other international criminals. In extreme cases, Gelbard said, the Clinton Administration could prohibit countries from electronic fund transfers with the United States--”very dramatic measures which would eliminate their ability to do business through the U.S. financial system.”

A senior official said the targeted countries include Venezuela, the Cayman Islands, Antigua, Thailand, Austria, Greece, Turkey and Cyprus, although some of those countries have indicated that they will adopt international standards against money laundering.

* A proposed international declaration on crime in which countries would agree to deny sanctuary to terrorists, narcotics traffickers and other trans-border criminals.

Clinton did not stay in the auditorium to listen to the first of three days of speeches by the likes of Yeltsin, Castro and Iranian Foreign Minister Ali Akbar Velayati. Instead, he slipped away for a series of private meetings, including one with South African President Nelson Mandela.

The President’s most important one-on-one sessions are scheduled for today, when he is to meet Yeltsin at the rural estate of former President Franklin D. Roosevelt in Hyde Park, N.Y., and Tuesday, when he is to meet Chinese President Jiang Zemin in Manhattan.