VIENNA, FEB. 14 -- Austrian Chancellor Franz Vranitzky threatened today to resign because he said the controversy raging around President Kurt Waldheim was preventing his government from dealing with other problems.

In his most critical comments yet about Waldheim, Vranitzky said the president had made only a "tiny start" in responding to a report by historians last week. Vranitzky questioned if the president could ever regain credibility.

The Socialist chancellor said in a television interview that Waldheim had not dealt seriously with the truth and that his backers must recognize opposition at home as well as abroad and not blame an "international Jewish conspiracy."

Vranitzky said the Socialist-led governing coalition with the conservative People's Party had made significant achievements since coming to power in January 1987 but that he now spent 60 percent of his work time on the Waldheim affair.

He said that if "within a forseeable time" he must continue in this way, "then I will not be able to take my other real duties seriously, and then the question will arise for me if I actually can go on in that way."

{In Hamburg, the West German news magazine Der Spiegal acknowledged that a purported 1942 telegram linking Waldheim to deportations of civilians to concentration camps was a fake, The Associated Press reported.}