The president of the United Steel Workers yesterday joined the American Steel Industry in urging the Carter administration to take quick steps to negotiate voluntary quotas on steel imports from Europe and Japan.

Lloyd McBride said at a press conference that unless the government acts swiftly, there will be further layoffs and more mill shutdowns across the country. Since mid-year, about 18,000 steel workers have been laid off and companies have closed down several million tons of capacity.

McBride's statement came two days before a special White House meeting designed to bring together steel makers, unions, steel users, consumers and steel importers to discuss the problem of rising steel imports.

McBride threatened to increase pressure on Congress to act if the Carter administration does not do something to stem flow of foreign steel. He told reporters that, while the administration had been cool to taking steps to restrict imports, he thinks that attitude is "changing. I'm optimistic."

But President Carter's chief trade negotiator, Robert Strauss, said in New York yesterday that the steel industry's problems go much deeper than imports and that he doubted if reduced imports "would have a serious impact on the problems of the steel industry."

Strauss said he has serious reservations about negotiating voluntary restraints on exports from major foreign steel producers (called orderly marketing arrangements), but said he could not rule them out.

Strauss said the steel industry's problems go long beyond imports. He cited "the very dramatic and very substantial over-production of steel," inefficient production facilities, lack of capital to modernize the industry and producers who feel the "answer is to raise prices to meet competitive shortfalls."

Strauss will lead the special White House meeting Thursday which also will serve to kick off a Treasury Department study of ways in which the government can assist the steel industry.

Strauss said the meeting is not a public relations ploy by the administration. "It's not a media debate," he insisted. "We're going to close the damned door and go at it."

Last month, Japan said it would be willing to negotiate voluntary limits on the amount of steel it ships to the United States, the chairman of the European Economic Community's steel producers association said and Monday that European producers also would be amenable to voluntary restraints.

The official, Jacques Ferry, said he wanted to "ward off the specter of protectionism and of a trade war which no one wants between Europe and the United States."

Strauss, who has negotiated orderly marketing agreements on shoes and color televisions, said neither Europe nor Japan has made any overtures to him about import restraints.

"No one has offered me anything," Strauss told reporters, "I don't accept any offers made in the newspapers."

World steel producers were rocked - and domestic producers pleased - by a treasury Department finding last month that Japan was dumping carbon steel plates in the United States, selling the product at prices below the cost of production.

If the government should find domestic makers and workers are being hurt by the dumping, then tariffs will be levied on the products.

U.S. Steel Corp, has filed further dumping charges against Japan, and other major steel companies are preparing charges against European steel makers.

Steel makers felt that last month's Treasury finding vindicated their charge that most foreign steel makers produced steel at a loss to maintain their employment, in effect exporting joblessness to the United States.

McBride talked with reporters after a mass meeting of elected union officials from Pennsylvania designed to put pressure on the Pennsylvania congressional delegation.