Robert J. Kane, president of the U.S. Olympic Committee, addressing the Executive Board of the International Olympic Committee today, urged formally that the 1980 Summer Olympics "be held at a site other than Moscow on the grounds that the contract between the ICC and the Moscow Olympic Organizing Committee has been broken."

In a strongly worded statement that will be presented to the full ICC membership in its session on Monday, Kane called the Soviet invasion of Afghanistan "an act of war by the Soviet Union against its neighbor that violates the fundamental principles of the ICC and of the Olympic movement."

In the first phrase of its official appeal to the ICC to move, postpone or cancel the Moscow Games unless Soviet troops are fully withdrawn from Afghanistan, a five-man USOC delegation similar in substance and language to those previously suggested by White House attorneys.

Asserting that "the Moscow Olympic Organizing Committee is made up of officials of the Soviet government the same government that launched the military invasion of a neighboring country without any provocation," rogated the spirit and the letter of the Olympic charter and therefore has become an unsuitable host for games intended to celebrate peace and international goodwill.

Secretary of State Cyrus R. Vance is expected to make the same point in a speech officially opening the IOC session on Saturday evening, and to reiterate President Carter's opposition to American participation if the Games go on as scheduled in Moscow and Soviet troops are not fully withdrawn from Afghanistan by Feb. 20.

IOC President Lord Killanin, who met privately with White House counsel Lloyd Cutler tonight and will meet informally with Vance before the IOC session opens Saturday night, has said that it is "legally and technically impossible" to move, postpone or cancel the Moscow Games.

Killanin and other IOC officials have said there are no grounds for stripping Moscow of the games because the organizers have violated no IOC rules, but Kane -- in a statement prepared with the assistance of Cutler and other White House aides -- argued otherwise.

After quoting the "fundamental principles" of the Olympic movement from the IOC Charter, Kane said: "If the city that has been awarded the Olympic Games is in a nation that ignores and cannot fulfill the basic aims of having those games build a better and more peaceful world, . . . then that city's contract with the IOC has been broken."

Kane went on to say that "the war-like attitude of the Soviet government also makes it inappropriate for the amateur athletes of the worldwide Olympic movement to parade past and therefore pay homage to the head of the Soviet Union and the military and civil leaders of that nation."

For these reasons, and "because the Olympic Games of 1980 should not be held in the capital of a country at war," Kane said, the Games should be moved to another site.

"If that is not possible, I request that the Games be postponed until such time as an alternative site can be found and prepared to host the next Olympic Games," Kane said. "If neither of these alternatives are feasible, I suggest that the 1980 Olympic Games be canceled."

Monique Berlioux, the IOC director, told a news conference that the executive board was considering Kane's request and that it would be discussed in the full IOC session.

"The situation is serious enough to take time and study and not make a statement which would jeopardize the Games one way or another," she added.

A State Department spokesman praised Kane's remarks as "a good statement that clearly lays out our position and states the facts."

The Los Angeles Times reported that Kane was upset with the Carter administration, however, for sending Vance to make a direct appeal to the IOC.

After a private meeting with Ignati T. Novikov, chairman of the Moscow Olympic Organizing Committee, Kane said the Soviets "are stepping into the breach, acting like diplomats," while the Carter administration "is making it easy for them by being heavy-handed," the Times reported.

Vance will make a frank and forceful speech setting out the Carter administration's position on the Olympics and calling for the U.S. and like-minded nations not to participate if the Games go on in Moscow, State Department sources said. They denied that Vance had requested to address the closed IOC session as well as the ceremonial opening of the session, which is open to the public.

Berlioux said that the IOC would not receive a copy of Vance's speech until he arrives in Lake Placid at 6 p.m. Saturday, about 2 1/2 hours before he speaks. Vance will be introduced individually to the IOC members in attendance at a traditional reception following the welcoming speeches by Vance, Kane and Killanin, she said.

Vice President Mondale has been designated by President Carter to open the Winter Games here on Wednesday.

Asked if today's presentation had opened room for negotiations on moving the Games from Moscow, Berlioux said: "For negotiations, no, but for thinking, yes."

The IOC announced that it will join the Lake Placid Olympic Organizing Committee (LPOOC) in appealing a ruling handed down by a New York State Supreme Court judge on Thursday that Taiwanese cross-country skier Liang Ren-Guay must be allowed to compete, using the traditional Nationalist flag and anthem -- though apparently not the name -- of the Republic of China. Liang, meanwhile will be admitted to the Olympic Village.

The LPOOC appeal will be heard on Monday afternoon by the Appellate Division of the State Supreme Court in Albany. Berlioux said there was no chance that Liang's suit would postpone the opening of the Winter Games.

Elsewhere, President Carter's boycott appeal suffered a double setback when Nigeria and Brazil announced they would send teams to Moscow.