Former U.N. secretary general Kurt Waldheim today dismissed as insignificant a recommendation by a U.S. Justice Department official responsible for investigating Nazi war crimes that he should be banned from the United States.

Waldheim repeated his assertion that all accusations of wrongdoing on his part will prove unfounded.

Austrian Foreign Minister Leopold Gratz said he had directed Austria's ambassador in Washington, Thomas Klestil, to clarify the action of the Justice Department official and report on its implications. Gratz said his ministry was prepared to represent Waldheim "as it would any Austrian citizen facing difficulties with U.S. authorities."

But the foreign minister pointedly added that, "It would be better to have a candidate, or eventually a president who speaks for Austria, who is not a case for the consulate and who is not so controversial that he requires the protection of Austrian diplomatic representatives." Waldheim is a candidate for president in the May 4 election here.

Gratz, in a radio interview here, criticized Waldheim for responding in different ways at home and abroad to charges that he deliberately covered up his wartime service in a command that perpetrated atrocities against Yugoslav partisans and deported Greek Jews to the Auschwitz death camp.

The foreign minister said Waldheim had appeared on American television to apologize for misleading people about his background while at home in Austria he triumphantly proclaimed that a smear campaign intended to sabotage his electoral prospects had collapsed. "This is like playing on two pianos," Gratz said.

Waldheim, who was campaigning in the province of Carynthia, issued a statement through his office today attacking the World Jewish Congress. Waldheim said the group had broken a promise to desist in its charges against him once the country's current president, Rudolf Kirchschlaeger, passed judgment on the validity of documents implicating Waldheim in wartime atrocities.

In a television address to the Austrian people Tuesday night, Kirchschlaeger declared that, based on the WJC papers he examined, he "would not dare to bring charges in a regular court." But Kirchschlaeger expressed doubts about Waldheim's claims to be ignorant of atrocities committed in the Balkans by his regiments.

The president said he would not pronounce Waldheim guilty or innocent and told the Austrian people they should decide by themselves for whom to vote in next week's election. But Waldheim quickly contended that Kirchschlaeger's remarks exonerated him of all charges.

Today's statement by Waldheim's office said, "The Justice Department recommendation is based . . . on an application by the World Jewish Congress, which thereby is continuing its campaign to damage Dr. Waldheim's reputation in contravention of its agreements with the Austrian head of state."

In New York, Eli M. Rosenbaum, the WJC general counsel, told The Washington Post it was "simply untrue" that his organization had made any agreement or promise to let Kirchschlaeger adjudicate the validity of its charges against Waldheim.

Rosenbaum said the WJC had called publicly for the Justice Department to investigate the case and decide whether Waldheim should be classified as an excludable alien. He noted, however, that the WJC had no power to compel the Justice Department to act and that the U.S. government had decided on its own to ask the United Nations for its secret file on Waldheim.

Rosenbaum also said that the WJC had provided documents it had found in various archives to the Austrian government for Kirchschlaeger's examination at Austria's request. He added that the WJC subsequently offered to give the Austrians additional documents discovered more recently but that the Austrian government had not responded to the offer.

Waldheim's spokesman, Gavy Christian, today said the candidate thought the Justice Department action was unimportant and wanted to avoid further comment because, "We're concentrating on winning an election and can't be bothered to react to every bureaucratic maneuver and ministries around the world."

Meanwhile, a group of more than 1,000 historians, artists and journalists calling themselves "New Austria" today urged Waldheim to withdraw from the presidential race.