The Reagan administration, bitterly disappointed by the violence that forced the cancellation of Haiti's presidential elections, yesterday urged the Caribbean nation's military rulers and political leaders to get "democracy back on the rails" by guaranteeing safe and honest new elections.

"The Haitian people showed very clearly that is what they want," State Department spokesman Charles E. Redman said. "They were turning out in large numbers at the polls {Sunday}. What needs to happen is for the authorities in Haiti -- the government, the political leadership, the candidates in the election -- to get together and do what is required to get this process moving again. It can be done."

Redman's remarks, coming after Washington's suspension Sunday night of $101.2 million in U.S. aid to Haiti, underscored how heavy a blow the election collapse was to U.S. policy there. After helping end the Duvalier family dictatorship in February 1986, the administration threw its support behind the army-dominated provisional government headed by Lt. Gen. Henri Namphy as the best hope for guiding Haiti, the poorest country in the Western Hemisphere, to democracy.

However, that approach ran counter to widespread popular feeling in Haiti that the army could not be trusted because of its 30-year ties to the Duvalier family and its reputation for corruption. In particular, many Haitians and outside observers, pointing to the political manuevering of recent months, had charged that Washington was overly tolerant of what looked increasingly like a Namphy attempt to do away with the elections and perpetuate himself in power.

U.S. officials, speaking on condition that they not be identified, acknowledged yesterday that what one called "a calculated-risk decision" had been made last year to avoid public scolding of Namphy's government in hopes it would make good on its promises of free elections.

In fact, the officials said, Richard N. Holwill, the deputy assistant secretary of state for Caribbean affairs, was ordered to decline an invitation to testify before the House subcommittee on Western Hemisphere affairs last week because the hearing was expected to become a forum for airing charges against the Namphy government.

"We can't run Haiti's elections," one official said in reference to the suggestion by Washington D.C. Del. Walter E. Fauntroy that the United States and other countries consider military intervention to ensure the safety of Haitian voters. He added:

"There also was the risk that if we lectured them too much, it would be counterproductive and result only in our being accused of meddling in their affairs. In private, though, we made our views unmistakably clear. Right until the last moment, we were very hopeful that the government would fulfill its responsibilities. The suspension of aid -- something that they need more than any other Latin American country -- is an unmistakably clear signal to them of how disappointed we were."

The officials indicated that there still is uncertainty within the administration about whether Namphy intends to defy U.S. displeasure and move to military dictatorship or whether the U.S. reaction will force the army to have second thoughts. Brunson McKinley, the U.S. ambassador in Port-au-Prince, met Namphy yesterday to deliver what the officials described as a "very stern message" from Washington. They added, though, that as of late yesterday, they had no information about what happened in the meeting.

Alluding to the ambivalence within the administration about the Namphy government, Redman said:

"The government has done a number of things. They have kept the process on the road, up until virtually the last day. It has not been an easy situation in Haiti. There was a long ways to go. There has to be established the grass roots mechanisms that democracy requires. It was our hope that this process could keep moving ahead. Obviously {Sunday} it broke down . . . in large part because there was not the necessary security to allow the elections to go forward."

Another senior official, talking about next steps, said, "The message given to Namphy yesterday was that we didn't think his dissolution of the civilian electoral council that tried to organize the voting was justified. We note that he indicated he still intends to surrender power on Feb. 7, and clearly we think the next step is for the provisional government to announce a new date for elections and procedures for ensuring that they take place on time and in safety."