President Carter signed a declaration with Indian Prime Minister Morarji Desai today proclaiming their government's commitment to reducing the threat of nuclear war and bridging the gap between rich and poor nations.

The Delhi Declaration, issued before the President left for Saudi Arabia instead of the usual joint communique, said: "We declare that war is not an acceptable means to settle political disputes." India and the United States pledged to resolve disputes with other nations amicably and through the United Nations.

"Existing stockpiles of nuclear weapons must be reduced and eventually eliminated, and the danger of proliferation of nuclear weapons must be arrested," it said.

Desai, however, said after Carter's departure that the nuclear powers should set an example before calling upon other nations to sign the Nuclear Non-Proliferation Treaty.

"The nuclear countries should themselves destroy these weapons," he said. "They should also sign a treaty to ban all tests. Only then they would have the moral right to ask other nations not to go in for any tests."

Both the United States and the Soviet Union have been pressing India to sign the Non-Proliferation Treaty and to accept international safeguards on all its nuclear facilities and operations in return for assured supplies of nuclear fuel.

Asked to comment on Carter's observation - inadvertantly made on a live microphone - that his administration would have to take a tough line in regard to nuclear safeguards, Desai said:

"There is nothing to react to as such. If there are safeguards which can be accepted, they will be. If there are difficulties, they would not be accepted."

The government spokesman drew attention to the fact that despite these differences. Carter had agreed to sell a further 7.6 metric tons of enriched uranium to India and that he had offered supplies of heavy water without a formal Indian request.

On the question of relations between rich and poor nations, the Delhi declaration said:

"The disparities in economic strength that exist among nations must be bridged and a more equitable international economic order fashioned if we are to secure international peace."