After more than two days of international wrangling, U.S. authorities continued holding a Soviet jetliner at New York's Kennedy Airport last night in an effort to determine whether ballerina Ludmila Vlasova was being forced to return to Moscow.

Throughout yesterday, the Ilyushin 62 jet sat on an airport tarmac, with Vlasova and 67 other Russian passengers on board, while U.S. and Soviet officials in New York, Washington and Moscow engaged in a tug of war over her status.

By last night, though, the impasse appeared no closer to resolution than when it began Friday night. Despite long hours of private negotiation and public exchanges of charges, the United States continued to insist on interviewing Vlasova and the Soviet Union continued to reject the U.S. demand as harassment of a Soviet citizen.

Vlasova, 36, is the wife of Alexander Godunov, 30, a leading Soviet dancer who defected from the touring Bolshoi Ballet last Thursday and was granted U.S. asylum. Godunov told U.S. officials he believed his wife might also want to remain in this country.

U.S. authorities then invoked a provision of federal law temporarily barring Vlasova's departure. Although the State Department says it twice informed the Soviet embassy here of that order, Soviet officials escorted Vlasova aboard an Aeroflot flight scheduled to leave New York for Moscow Friday evening -- a move that led federal authorities to block the plane's departure.

State Department officials continued to stress last night that they are bound by U.S. and international law, as well as by humanitarian considerations, to prevent the involuntary repatriation of anyone from U.S. territory.

As a result, they said, it is necessary to talk with Vlasova and ascertain her wishes in an environment where she can feel free of duress. They have insisted that this means interviewing her outside the airplane, because the United States has no legal jurisdiction aboard.

The international attention being directed at the impasse yesterday prompted reports that President Carter, who is weekending at Camp David, was personally making the policy decisions about the impasse.

However, State Department sources privately characterized such reports as an overstatement. They said that while Carter was being kept informed and that U.S. officials were acting in accordance with his general policy instructions, the American effort was being directed by Acting Secretary of State Warren M. Christopher.

These sources also stressed that there has been no change in the U.S. position that Vlasova must be interviewed outside the airplane. Earlier yesterday, Donald F. McHenry, the deputy United Nations ambassador who is in charge of U.S. negotiations with the Soviets in New York, told reporters there that the United States might be willing to compromise and talk with Vlasova aboard the plane.

However, the department sources, although they would not elaborate or say specifically that McHenry's idea had been countermanded, reiterated last night that Washington does not consider an interview on the plane an acceptable way of resolving the matter.

The Soviets, though, took exactly the opposite tack. Boris N. Davydov, a spokesman for the Soviet embassy here, said last night, "If the Americans wish, they can at any time send representatives on board the plane and talk with her."

Davydov said his government was willing to be "flexible" about arranging an interview on the plane in a matter satisfactory to the United States. This, flexibility, he said, extends to questions of who would be present at the interview and whether the other passengers and crew would cooperate in allowing privacy for the interview.

But, Davydov insisted, in refusing to allow Vlasova to be taken from the plane, the Soviet government was "acting in accordance with her own wishes." He added: "The Soviet side continues to insist that the plane should be promptly allowed to leave."

While what one U.S. official at Kennedy Airport called "the international gunfight at the O.K. Corral" continued, Pan American Airways, whose terminal at Kennedy is used by Aeroflot, tried to keep those on board as comfortable as possible.

A large portable generator was connected to the plane Saturday to provide air conditioning from outside in the sweltering New York weather, and Pan American provided the passengers with food and liquor as well.

McHenry said Saturday the passengers were free to leave the plane and await the resolution of the dispute, as did a group of American passengers originally due to take the flight. But the Russians elected to stay on board, and although there has been no indication of illness among them, it was assumed by observers outside that conditions on the plane must be increasingly uncomfortable.

Godunov was not present at the airport yesterday. But Orville Schell, a New York attorney representing him, said that they are in touch, that Godunov "is available" if his presence would help and that the dancer wants to be reunited with his wife. Schell refused to disclose where Godunov is staying.

The attorney praised U.S. actions, saying, "You couldn't ask for a better performance." He especially cited "the tremendous imagination, diligence and good will" of McHenry, his staff at the airport and officials in Washington.

Anti-communist demonstrators who showed up Saturday continued their vigil yesterday. But this time, their chanting and waving of banners was confined to the roof of the Pan American terminal rather than on the ground near the plane.

By last night, the physical scene at the plane's gate looked almost the same as it had when the affair began on Friday evening. McHenry, looking remarkably fresh despite his almost around-the-clock participation, conferred with aides in one part of a room cordoned off by police, while his Soviet counterparts huddled in another corner.

A crowd of approximately 75 reporters and photographers watched and waited behind a barrier, and almost three days of keeping vigil over events that seemed frozen began taking its toll among the press yesterday.

At one point, a herd of reporters stampeded after McHenry as he left the cordoned area, only to learn that he was heading for the men's room. Later, the reporters surrounded an elderly woman in a wheel chair in the belief she had been taken off the Aeroflot flight. She talked affably about her experiences -- but only to reveal that she had been on an entirely different flight.