Undersecretary of State Lawrence S. Eagleburger expressed optimism yesterday that the United States and its European allies can, over time, forge a common position on financial credits to the Soviet bloc.

In a question-and-answer session with Overseas Writers, a group of diplomatic journalists, Eagleburger called the credit issue "an important strategic question" for the rest of the century.

In the recent past, Western financing for the East has been "unrestrained" and "chaotic," with a loss of strategic leverage and such untoward financial consequences as the accumulation of a $27 billion Polish debt, according to Eagleburger.

He said the recent trip to Europe by a team headed by Undersecretary of State James L. Buckley had "begun a process of discussion" with European leaders about common restrictions on future credits. But Eagleburger made no claim of agreement, even on broad principles, about national policies in this field.

Leaders of the 10-nation European Economic Community, meeting in Brussels, said in a communique yesterday that future credits for the Soviets should be the subject of a study.

That very general statement was taken here as the charter for future U.S.-European discussions on the subject following up the Buckley mission. State Department spokesman Dean Fischer went out of his way to praise the EEC for approving a study.

Eagleburger said the administration continues to oppose the planned Soviet-Western Europe natural gas pipeline, but he hinted that there is no way to stop it. In his view, he said, the pipeline is an issue that should have been solved five years ago rather than today, suggesting that U.S. action now would be ineffective.

Asked about President Reagan's warnings following imposition of martial law in Poland that additional U.S. actions could be taken if repression continues, Eagleburger said that, in his view, existing sanctions are "sufficient."

"I want to be very careful. There are obviously other steps we can take. I simply want to make it clear that at this point there are no steps we are about to impose. Those steps remain available to us if we should decide to use them," he said.

Among measures still under consideration are a declaration of default against Poland because of failure to maintain scheduled payments on its debt to the West. But Eagleburger indicated that, as in the past, the State Department opposes this.

Despite the absence of any clear sign of moderation in Poland, Eagleburger hinted that the administration will soon decide to reopen strategic arms talks with the Soviet Union.

An earlier U.S. plan called for Secretary of State Alexander M. Haig Jr. and Soviet Foreign Minister Andrei Gromyko, in their meeting late last January, to establish a date for renewal of these negotiations, but this move was shelved by the United States in a show of displeasure over the crackdown in Poland.

The essential decision now, Eagleburger said, is whether new strategic arms negotiations "are important enough, in the context of the international situation, to believe that they ought to begin."

He discussed recent warnings from Moscow of unspecified retaliation against U.S. territory if U.S. Pershing II missiles are deployed near Soviet borders in Western Europe. Some Soviets have said that this warning refers to placement of Soviet missiles in Cuba, while other Soviets have said this is not the case, according to Eagleburger.

In any event, he said, it is necessary to take the warning seriously and to let the Soviet Union know the seriousness of U.S. concern. State Department sources said Moscow has been given notice on this point through diplomatic channels.