Andrew Young, U.S. ambassador to the United Nations, today criticized Cuba's treatment of its domestic dissidents and said human rights questions will play a role in the move toward improved U.S.-Cuban relations.

It was Young's bluntest criticism of President Fidel Castro's government since he became ambassador to the United Nations early this year.

Previously, Young had been criticized heavily by anti-Castro forces in the United States for saying that Cuban military advisers helping the Marxist forces in the Angolan civil war might prove to be a stabilizing element in that country.

Young's comments on his Caribbean swing have largely supported the idea of improved ties. In Surinam yesterday, for example, he said that the Cubans "are not supermen" and that it was irrational for the United States to fear a Cuban presence in Africa or Cuba's position within the Western Hemisphere.

At a press conference here today, however, Young was asked whether he is satisfied with the Castro government's recognition of human rights within Cuba and he replied: "No, I'm not."

He cited such situations as the imprisoning of political dissidents, governmental control of the press and the suppression of all political groups except the Cuban Communist Party.

"I think those are considerations that become quite important if and when we move toward a normalization of relations," he said.

News agencies reported from Trinidad:

Young, warning that America will not support dictatorships that "pull people's fingernails out," said the United States should help stabilize democracies with economic aid.

Young continued talks today with Eric Williams, prime minister of the twin island nation of Trinidad and Tobago, before flying to Venezuela, the seventh stop on his 10-nation Caribbean tour.

Defending the Carter administration's human rights initiatives, Young said last night that "I don't mind raising a little hell about it. (human rights abuses)."