BONN, West Germany (AP) _ President Richard von Weizsaecker has agreed to meet informally with Austrian President Kurt Waldheim, who has been shunned by many nations because of his alleged involvement in Nazi war crimes.

But government officials denied Thursday that the meeting was intended to help break the diplomatic isolation Waldheim has faced since taking office last year.

''There is a long tradition of good-neighbor talks between our two countries,'' one informed government official said in an interview.

''There is nothing more or less than that to this,'' said the official, who commented on condition of anonymity.

No date has yet been set for the meeting.

The U.S. Justice Department placed Waldheim on its list of undesirable aliens earlier this year, barring him from entering the country.

Waldheim, a former secretary-general of the United Nations, has been accused of helping ship Jews and Yugoslav partisans to concentration camps as a young officer in the German army in the Balkans during World War II.

Last month, the Austrian president visited the Vatican in his first official trip abroad since he was elected in June 1986. Israeli leaders sharply criticized the Vatican for inviting Waldheim.

Waldheim made his second trip abroad last week when he visited Jordan. He has received invitations from several other Arab countries.

While Waldheim has obtained invitations from Hungary and several Third World nations, the planned meeting with Weizsaecker would be the first that has been disclosed involving a leader of a western European nation.

On Thursday, Soviet premier Nikolai I. Ryzhkov, on a visit intended to boost flagging trade with Austria, met with Waldheim in Vienna but did not invite the president to visit the Soviet Union, Austrian officials said.

Weizsaecker, a German army soldier during World War II, won worldwide praise for a speech he delivered to the Bonn parliament on May 8, 1985, marking the 40th annivesary of Nazi Germany's surrender at the end of World War II.

Weizsaecker urged all Germans to remember the crimes of the Nazi era.