Haiti's new military ruler pledged today to hand over power to a democratically elected government and usher in a new era of political freedom in this traditionally downtrodden country.

"We are going to work for the blooming of real and functional democracy founded on absolute respect for human rights, press freedom, the existence of free labor unions and the functioning of structured political parties," said Lt. Gen. Henri Namphy, president of the National Council of Government, as he installed a new Cabinet in the national palace.

"We are aware that the country aspires to the elaboration of a liberal constitution, to the rebuilding of a legislative power that is the product of free elections and to presidential elections with direct, universal suffrage. Such is the program of this provisional government, eager to hand over power to a democratically elected government, which is an indispensible condition for the social stability and harmonious development of our country."

Namphy's declaration stopped short of setting a time for the election, however, and Marcel Leger, the new minister of finance and economy, said the government has not considered fixing a date for voting yet because of pressing problems that require urgent attention first.

The statement by Namphy nevertheless put the ruling council on record with a promise that elections will be held and that the Duvalier constitution will be replaced with a system designed for democratic rule and direct presidential elections after 29 years of a family dictatorship.

This was considered a key step for Namphy and his council colleagues, who were named by president Jean-Claude Duvalier eight hours before he flew into exile early Friday. Although Namphy had said earlier that the members of the council had no political ambitions, today's declaration was an explicit pledge to the Haitian people to steer the country toward representative democracy and guarantee political freedoms denied under Duvalier.

U.S. officials had said that the Reagan administration was watching to see what the council does on these issues before making any decision on emergency aid for Haiti. Namphy met for several hours Saturday with U.S. Ambassador Clayton McManaway, and U.S. aid was reported to have been a topic of the conversation.

The Reagan administration originally requested $56 million in aid for Haiti in fiscal 1986. But the Duvalier government's human rights abuses had thrown that request into doubt. In addition, some U.S. aid payments from previously approved funds were being held up for the same reason when the government fell.

In another step likely to enhance the chances of aid, the government's National Radio announced formal dissolution of the Volunteers for National Security, the notorious political police popularly known as Ton-Tons Macoutes that was started by Duvalier's father, Francois (Papa Doc) Duvalier. The decree, dated Saturday but published today, said: "The armed forces of Haiti remain the only legal institution responsible for the defense of the integrity of the national territory and the maintenance of order and public security."

Several hundred Haitian youths demonstrated outside the presidential palace and Army headquarters to dramatize their joy over the demise of the Ton-Tons Macoutes as a power here. "This year, no more Macoutes," they chanted, brandishing shreds of the blue-denim uniform worn by the Volunteers for National Security.

Some of the laughing demonstrators held up a dog dressed in torn sections of the uniform. In another part of town, a blue hat from the uniform dangled from a tree as if after a hanging.

A number of Ton-Tons Macoutes have been killed by enraged Haitians since Duvalier's departure. Lt. Alix Calixte of the Presidential Guard said several dozen have sought refuge with the Army, which has taken them into barracks near the palace to protect them. Their fate has not been decided, he added.

The council includes Namphy, Cols. Williams Regala and Max Valles along with two civilians, Alix Cineas and Gerard Gourgue. Duvalier also named Col. Prosper Avril as adviser, ensuring cooperation from Avril's friends in key Army commands, a highly placed Haitian source explained.

Within hours of Duvalier's departure, the council suspended the constitution, dissolved the legislature and asserted the right to rule by decree.

Most of the 13 members of the new Cabinet had been active in government under the Duvaliers. As a result, some Haitians have begun to complain that none of Duvalier's most vocal opponents was called into service to underline what they hope will be a dramatic departure from former times.

The ruling officers appear primarily concerned for the moment with maintaining a fragile public order and getting the government back to work. A 2 p.m.-to-6 a.m. curfew imposed Saturday was pushed back yesterday to 6 p.m., but soldiers continued to patrol the streets.