The Japanese government yesterday flatly rejected charges by other major industrial nations that it is not doing enough to reduce its burgeoning trade surplus, but indicated Tokyo might be receptive to some U.S. initiatives for holding down Japanese steel exports.

Breaking a month-long silence on the issue, Hiromu Fukada, economic minister at the Japanese embassy here, called in reporters to declare firmly that "in short, Japan is doing all it promised to do - and more - as a contribution to world economic recovery."

At the same time, Fukada said Japan is "prepared to study any reasonable proposal" for resolving its dispute with the U.S. over steel imports here - including an agreement to set voluntary export quotas, which he listed as "definitely one of the possibilities."

Fukada also rejected out of hand a suggestion by H. Johannes Witteveen, managing-director of the International Monetary Fund, that Japan turn to tax cuts rather than increased spending as a means of spurring its lagging economy.

The minister contended that tax reductions would not help in the Japanese economy because cautious consumers would only place their rebates into savings. He asserted the Japanese system for channeling public works monies through local governments would produce a quick impact.

The carefully prepared response marked a dramatic shift in tactics for the Japanese, who traditionally have confined such pronouncements to diplomatic channels. The session was the first in recent memory where officials have answered U.S. criticism publicly in this fashion.

Japanese officials were silent at last month's International Monetary Fund meeting in the face of severe criticism from Western finance ministers, who charged that Tokyo's recalcitrance on the trade surplus issue was threatening worldwide economic stability.

At the same time, the response appeared to have been timed deliberately. The White House has scheduled a meeting with steel industry officials this morning at which a major source of complaint is expected to be Japanese penetration of the U.S. steel market.

In their remarks yesterday, Japanese officials made these points:

Fukada conceded that Japan "so far . . . has not been successful" in reducing its balance of payments surplus - a move Western powers say is crucial to spurring a vigorous world-wide economic recovery. But he insisted the surplus was "quite unexpected."

The minister said Japan had aimed originally at running a $700 million deficit, but so far that has turned into a $6.5 billion surplus. He declined to comment on estimates by U.S. officials that the surplus actually may approach $8 billion to $9 billion.

Yoshio Kawahara, the embassy's commercial minister, said Japanese industry "wants to negotiate any proposal from the U.S." for easing the current dispute over steel imports her - including a so-called "orderly marketing agreement," or voluntary export quotas.

While not actually promising agreement on any such effort, Kawahara emphasized that Japanese steelmakers were anxious to avoid "disrupting the market" in the U.S. which the regard as a primary customer. He said Japanese officials were here in August prepared to negotiate, but the Carter administration did not want to talk.

Fukada indicated that as a result of new joint initiatives to spur U.S. exports to Japan, Tokyo expected to see more exports of U.S.-made passenger cars, office equipment and aircraft. But he said Japan would not soon ease its marketing restrictions, which often force U.S. manufacturers to sell their goods at triple their domestic price.

In discussing the possibility of a steel-export agreement, Fukada made clear that any such move would be regarded as a short-term measure. He indicated that Japan agreed with the Carter administration that any genuine solution should be worked out in worldwide talks.

In a rare display of public candor, the Japanese officials indicated they had been shocked an dembittered by the critism at the IMF meeting. Fukada admitted later that "we're kneely aware of the somewhat tense climate - atmosphere - concerning some of our policies."

The minister told reporters that in the wake of the IMF criticism, "our intention to see that these projects (for added economic stimulus to the Japanese economy) will be accelerated." At the same time, however, he offered no new hope that the deficit would be reduced soon.

The unusual session was arranged by the U.S.-Japan Trade Council, the official U.S. lobbying arm of the Japanese government.