France is urging its West European partners to set themselves apart from the United States on a number of issues at the summit of industrialized countries in Bonn starting Thursday, from the proposed new trade negotiations to President Reagan's Strategic Defense Initiative.

As President Reagan left Washington for Bonn and other summit participants began gathering in the West German capital, French officials made clear that they intend to take the lead in attempting to formulate European viewpoints, clearly distinguished from Washington's positions.

In a series of public statements and private briefings for journalists, officials from President Francois Mitterrand on down also depicted France as a spokesman for Third World interests at the three-day summit.

Presidential spokesman Michel Vauzelle told journalists today that France's Socialist government saw the Bonn summit as an opportunity to measure Western Europe's "political will" to exist as an independent entity. He singled out technological research and preparations for new trade talks as key areas in which European countries could display their independence.

Mitterrand already has called on other West European leaders to coordinate their response to the Reagan administration's invitation to join in research into the SDI, or "Star Wars," as the American project is more popularly known.

The French president also has opposed Washington's wish to set a firm date for a new round of global trade talks as long as there is no significant progress on calling an international conference on monetary problems.

Vauzelle said France would be anxious to see whether other European countries were ready to "preserve the identity of Europe" by supporting French positions at the Bonn summit. Other European Community countries represented at the summit are West Germany, Britain, and Italy.

While French officials deny that they are seeking a confrontation with the United States at the summit, they make no secret of their wish to influence the transatlantic debate by generating alternative political ideas to those of the Reagan administration.

Elsewhere in Europe, however, French attempts to develop independent positions have met with only partial success. With each European country defending its own interests, there is little sign of common European positions emerging either on Star Wars or on trade and monetary issues.

Japanese Prime Minister Yasuhiro Nakasone, arriving in Bonn today for a state visit prior to the economic summit, joined West German Chancellor Helmut Kohl in saying that the research phase of Reagan's SDI was justified by Soviet efforts in the space- based defenses.

Both leaders stressed, however, that the U.S. program must not be allowed to violate earlier arms control treaties or be exploited in a way that seeks to establish superiority over the Soviet Union, according to a spokesman for Kohl.

Here in Paris, Socialist Party Secretary Lionel Jospin commented after meeting with Mitterrand on his preparations for the summit: "It is striking to see that, apart from the United States, the other source of reflection and ideas, particularly in the European countries, is France."

As is customary, Mitterrand also called in leaders of the right-wing opposition this week for consultations prior to the Bonn summit in an attempt to demonstrate that there is a consensus in France on foreign policy.

French aspirations to stimulate Europe to counter the technological and economic challenge posed by the United States date back to Charles de Gaulle's vision of Europe as a third force in world affairs.

The traditional French approach to the European Community was neatly summed up by Mitterrand in a television interview on Sunday when he said that Europe could "magnify" France's voice in world affairs.

In a rare display of bipartisan unity, opposition politicians have voiced support for the Socialist government's attempts to persuade other European countries to take part in a joint high-technology research project known as Eureka.

Although theoretically restricted to "civilian" technology, the Eureka project covers much of the same ground as SDI, including laser beams and artificial intelligence.

Briefing journalists today, Vauzelle said France believed that progress toward a new round of talks under the General Agreement on Tariffs and Trade should run parallel to progress toward an international monetary conference. The Reagan administration has been pressing for an agreement to open trade talks by the beginning of 1986.

Among the arguments cited by French officials against fixing a precise date for the trade talks is the opposition of developing countries, the need for detailed preparations, and skepticism that such a step would indeed ease protectionist pressures in the United States, as Washington has argued.

France is also pressing for discussion at the Bonn summit of a series of measures designed to relieve famine in Africa, including the development of satellite early warning systems on crop failures, the setting up of rapid-transport units, and a coordinated program to halt the spread of deserts.

Nakasone, backing the Reagan administration's line, urged Kohl to persuade his European allies to support the new trade round. A Japanese spokesman said Nakasone stressed that the uncertain outlook for world economy made the round important.

The two leaders declared that a summit meeting between Soviet leader Mikhail Gorbachev and Reagan would be a "welcome step" that could help reduce East-West tensions. They also exhorted the superpowers to achieve early progress at the Geneva arms talks.

While indicating their interest in joining the SDI research program, both leaders said they wanted to hold further talks with Washington about the nature of the program. They also stipulated five conditions that they considered imperative before participating in the project.

Kohl and Nakasone agreed that the present system of nuclear deterrence must be maintained, that SDI research must be compatible with the 1970 antiballistic missile treaty and that the United States should not strive for unilateral superiority.

They also contended that consultations were necessary with the Soviet Union before moving ahead toward any "realization" or development of the research. Finally, they said that the SDI project must not be a "technological one-way street" for the United States and that there must be a guarantee that research findings will be exchanged among all participating allies.

In his speech prepared for delivery at a dinner for Nakasone this evening, Kohl said, "We hope for closer cooperation in future technologies without national jealousies."