Two of Eastern Europe's most independent leaders began official visits in Western Europe today, becoming the first Warsaw Pact heads of state to travel to NATO capitals since the Soviet Union walked out of nuclear arms control talks last year.

Romania's President Nicolae Ceausescu arrived in Bonn today for three days of talks with Chancellor Helmut Kohl and other West German politicians.

Meanwhile, Hungary's Janos Kadar embarked on a two-day trip to Paris, the first official visit to France by a Soviet Bloc leader since President Francois Mitterrand took power in 1981.

The timing of the visits to Paris and Bonn appears to be coincidental. They are expected to focus on how the European countries can revive detente through enhanced trading ties and arms control efforts and reflect the persistent desire of smaller countries in both blocs to find ways to rebuild an East-West dialogue in spite of the continuing tensions between Moscow and Washington.

East European leaders have been especially uncomfortable with Moscow's earlier attempts to freeze East-West relations in retaliation for the deployment of Pershing II and cruise nuclear missiles in Western Europe.

A strong yearning within the East Bloc to renew contacts with the West is considered by diplomats to be a major factor in Moscow's decision permitting the recent meeting between Foreign Minister Andrei Gromyko and President Reagan.

For their part, West Europeans have started to move ahead of the United States in restoring normal relations with Poland through a series of high-level visits this autumn.

Unlike East German leader Erich Honecker and Bulgaria's President Todor Zhivkov, who succumbed to Soviet pressure and postponed trips last month to West Germany, Ceausescu decided to proceed with his visit even though its duration was cut by two days.

Ceausescu, who has long pursued a maverick course in foreign policy, emphasized in a newspaper interview today that European countries "must act themselves without waiting for the results of negotiations between the United States and the Soviet Union."

He told the West German daily Die Welt that "we must work to outgrow military blocs and steadily reduce their role until their simultaneous dissolution."

In a speech welcoming the Romanian leader, West German President Richard von Weizsaecker said "your visit shows that you share our belief that the medium-sized nations of our continent also have a duty to contribute to stabilization and development in Europe and the world."

Like Romania, Hungary has been seeking to expand relations with the West despite the chilly climate between the superpowers.

Earlier this year, in what was regarded as brazen defiance of Moscow's aims, Kadar hosted state visits by government leaders from West Germany, Britain and Italy-the three Western countries accepting the new missiles.

His meetings with Mitterrand, who staunchly supported the NATO missile deployments and has maintained cool relations with the Kremlin since his Socialist party came into power, are intended to broaden Hungary's political and economic ties with the West.

Despite praise for Ceausescu's independent ways, foreign ministry officials in Bonn said they expect serious differences could arise over how to inject new momentum in the moribund arms control negotiations.

Ceausescu believes that the United States should take the "first step" to break the deadlock because the new U.S. missiles provoked the collapse of the arms talks.

He suggested that the United States should freeze the deployment of Pershing II and cruise missiles in Europe. In return, the Soviet Union should halt what he called "countermeasures" such as deployment of the short- and medium-range nuclear missiles that have been stationed recently in East Germany and Czechoslovakia.

"Nothing justifies these measures, on either side, and it is necessary to stop in order to reopen negotiations between the superpowers," he was quoted as saying in the Die Welt interview.

The Soviet Union has insisted that NATO must remove the new missiles before arms control talks can resume. West Germany has continued to back the U.S. view that negotiations should begin without concessions by the West, otherwise the Soviets would be rewarded for walking out of the Geneva talks last year.

NATO contends that its intermediate-range missiles are being deployed in response to the Soviet SS20s aimed at western Europe and can only be withdrawn as part of an equitable arms control agreement.

"When it comes to getting the talks started again, Ceausescu is closer to the Soviet viewpoint than most people realize," said an East-West specialist in Bonn. "We don't expect to see much progress toward a merging of our positions."

Following the disappointment of the canceled trips by the East German and Bulgarian leaders, the Kohl government appears eager to demonstrate that its channels of cooperation with Eastern Europe have not been shut down.

Ceausescu is being accorded full military honors and may reap some new promises of economic assistance from West Germany, which is Romania's biggest trading partner outside the Communist world.

Both Romania and Hungary have refrained from participating in a Soviet-led propaganda campaign accusing the Bonn government of trying to reclaim East European territories under the guise of a quest for German reunification.

The intensity of Moscow's criticism compelled Honecker to cool the growing rapprochement between the two Germanys and to cancel plans for a September visit to West Germany.

While the Bonn government may be prepared to show its appreciation for Romania's refusal to join in Moscow's rhetorical broadsides, Kohl is still concerned about the fate of large numbers of ethnic Germans in Romania, whose ancestors settled there seven centuries ago.

About 1,300 are now being allowed to emigrate each month, according to Bonn officials, but the government would like to see more restrictions removed.

The West German Red Cross said today that the Romanian officials have been extorting huge bribes from ethnic Germans trying to leave for the West.

Ceausescu, however, has claimed that people who have lived in Romania for more than 700 years "can have no other fatherland" and should remain in the country of their birth.