Closing the gap between rich and poor nations quickly is vital not as a matter of charity or morality, but as a matter of mankind's survival, an independent commission chaired by former West German chancellor Willy Brandt declared today.

The commission charged that an absence of political will and failure of political courage have allowed relations between rich and poor, called the North-South dialogue, to founder.

Brandt conceded in a press conference today, on presentation of the report here, that the commission's call for a North-South summit, one of its principal recommendations, is made much more difficult by the high tensions following the Soviet invasion of Afghanistan.

The failure of lower-level politicians and technocrats to make significant progress on North-South problems was highlighted by the discordant U.N. Industrial Development Oranization conference in New Delhi last week.

The Brandt Commission was formed to seek solutions acceptable to the rich and poor where delegates under instructions from their governments, such as in New Delhi, have failed.

The New Delhi conference broke down when the United States and other Western nations rejected a proposal that they put up $300 billion in a global fund to aid the poorer nations.

The final report of the Brandt Commission makes more modest demands on the rich. It calls for $8 billion a year in new food aid and a goal of $50 billion to $600 billion in development funds by 1985, compared to $20 billion today.

World Bank President Robert S. McNamara first suggested an independent commission chaired by Brandt as a way around the political and bureaucratic rigidities that have stifled North-South contacts.

"There isn't a political dialogue," commission member Shridath Ramphal of Guyana, who is secretary general of the British Commonwealth, said here today. "The North meets. The South meets, but they rarely have contacts with each other."

Among the major recommendations of the 18-member group, formally called the Independent Commission on International Development, are:

An international tax on trade, with the heaviest tax on weapons sales. This income would be used to benefit the developing countries.

All agreement between oil producers and oil consumers that would ensure regular supplies of oil, make price increases predictable and gradual, promote conservation and ensure major investment in oil exploration and development in the Third World.

Reform of the monetary system, substituting an international currency for the dollar.

Consideration of a World Development Fund, which, unlike the World Bank, would include the communist nations.

Some of the ideas advocated by the commission are old hat, Ramphal told reporters, but if they have been voiced before, they have never been acted upon.

The suggestion of a summit involving about 25 leaders of nations representing the "major world groupings" is one of the commission's original contributions.

Brandt stressed to reporters that such a summit can still be possible despite new U.S.-Soviet tensions, and he said it should be conducted with the minimum of pomp and publicity.

The leaders who attend would be unable to make commitments on behalf of others, but the Brandt Commission urged a summit because "we believe the present deadlock is so serious, and the need to break through is so evident, that nothing should delay discussion and negotiation at the highest level."

After presenting a copy of the report to U.N. Secretary General Kurt Waldheim today, memebers of the commission will meet with Carter administration officials Wednesday.

In addition to its urgent warning that the troubles of the international monetary system are likely to worsen and its appeal for new methods of handling international energy relationships which threaten to become unmanageable, the Brandt report repeatedly has denounced the world's waste of resources on arms.

Total spending for arms is approaching $450 billion annually and seems likely to soon hit $1 million a minute, the report said. That sum dwarfs what is being spent for development of the Third World for public health. The report gives as an example:

"One-half of one percent of one years world military expenditures would pay for all the farm equipment needed to increase food production and approach self-sufficiency in food-deficit low-income countries by 1990."

The commission members included four former government chiefs -- Brandt, Olof Palme of Sweden, Edward Heath of Britain and Eduardo Frei of Chile. Other members were business, political and economic leaders from the United States, Canada, France, Japan, Kuwait, India, Indonesia, Algeria and Tanzania.

The U.S. members were Peter Peterson, former commerce secretary and board chairman of Lehman Brothers Kuhn Loeb Inc., and Katharine Graham, chairman of the board of The Washington Post Co.

Graham said this report should help to move the dialogue along. "Not addressing these questions bears a heavy cost."