A Romanian circus acrobat told immigration officials in New York yesterday he did not want to defect after the officials, believing he might be leaving the country against his will, stopped him from boarding a plane to Romania, Immigration and Naturalization Service officials said.

INS officials stopped Andi Georgescu, 24, from boarding a plane Wednesday at Kennedy International Airport hours after Georgescu's American girlfriend, Cheri Meyer, 21, of Mesa, Ariz., phoned the local office of Sen. Dennis DeConcini (D-Ariz.) and complained that Georgescu, who she said wanted to marry her, was leaving the country on a 9 p.m. flight to Romania via West Germany against his will. According to DeConcini staff members, the woman told them she was pregnant by Georgescu.

A member of DeConcini's Arizona staff, Marcos Andrade, said he phoned the State Department, which contacted INS.

INS officials found Georgescu at the airport, took him to a naval facility overnight, and interviewed him yesterday morning at the INS office in Manhattan out of the presence of Romanian officials, said INS spokesman Duke Austin. He added that Georgescu did not request political asylum. Later, Georgescu spent two hours speaking to a member of DeConcini's staff, Tim Carlsgaard, and said toward the end of the two hours that he wanted to return to Romania, DeConcini said at a press conference yesterday.

"Based on the past experience in New Orleans, I was very concerned that we didn't put him on the first plane to Romania last night," DeConcini said. He was referring to an incident in Louisiana last month in which INS officials returned a Russian sailor, Miroslav Medvid, to his ship after the sailor swam ashore and told an interpreter he wanted to defect.

DeConcini said he and Carlsgaard were convinced that Georgescu was leaving the country of his free will. "He was not under any kind of sedative or foreign substance that would have influenced his ability to think or make decisions," DeConcini said in response to questions.

Georgescu and six other Romanian acrobats had a two-year contract with Ringling Bros. and Barnum & Bailey Circus. The other Romanians in the troupe left the United States on a scheduled flight Wednesday night, Austin said.

Austin rejected suggestions that INS officials rushed to help Georgescu because of the criticism the service encountered over its handling of the Medvid incident. "I'd like to think that INS would have acted this way if there had been a Medvid case or not," said Austin, who cited a 1979 case, involving Soviet ballerina Ludmila Vlasova, in which INS' response was similar to its response in the current case.

Austin said INS evaluates such situations on a "case by case" basis and decided to intervene in this case because it was not simply a "crank call" but a request from the State Department and DeConcini. Meyer told DeConcini's staff members that Georgescu had phoned her Monday and Tuesday, saying he wanted to be with her but thought he was being followed. DeConcini said Georgescu had booked a flight to Arizona.

Carlsgarrd said Georgescu told him he was willing to marry the woman if she came to Romania and that he was concerned that if he stayed in the United States his parents might be punished. Georgescu said his father was a government official in Romania.