President Reagan has been urged directly by senior U.S. diplomats here to visit the Bergen-Belsen former concentration camp on May 5, the same day he is slated to lay a wreath at a German military cemetery in Bitburg, where the graves of more than 30 Nazi SS troops are included among the 2,000 soldiers buried there, according to well-informed diplomatic sources.

As recriminations mounted over who was responsible for the uproar engulfing President Reagan's plans for his state visit to West Germany next month, a U.S. advance team, led by White House deputy chief of staff Michael K. Deaver, examined onetime concentration camps at Bergen-Belsen, Dachau and Flossenburg in southeastern Bavaria as well as a synagogue at Worms as possible sites for a ceremony, according to U.S. and West German sources.

The criticism from Jewish and veterans' groups over the handling of Reagan's itinerary for the West German visit May 1-6 has created tensions not only between the U.S. and West German governments, but also between U.S. diplomats and the White House advance team.

The conflict within the administration has grown particularly acute because President Reagan is known to be distraught over the controversy. The Rev. Billy Graham, who visited the president this week, found him to be so wounded by charges of insensitivity to the Jewish victims of the Nazi regime that he was close to tears, senior diplomatic sources said.

"It's not the president's fault; he has been badly served," a top U.S. diplomat said. "If they had left the preparations to the State Department and West German Foreign Ministry, instead of doing this through the White House and the chancellery, we would not have this mess."

The Bergen-Belsen camp is being advocated because it is a powerful symbol of the Holocaust. While Dachau is equally infamous, it would be considered politically embarrassing for Reagan to accept Dachau after having rejected it earlier. The Flossenburg camp is not so well known, and the Worms synagogue could spark new criticism flap because Reagan already has gone on record as saying he now intends to visit a former concentration camp.

The Bonn government, which initially suggested Dachau, still favors that site since Chancellor Helmut Kohl has already accepted an invitation from German Jewish groups to address a ceremonial service at Bergen-Belsen on April 21. The chancellor is said to be reluctant to make a repeat appearance, but West German President Richard von Weizsaecker could stand in, according to protocol.

"We allowed the Germans to keep the Bitburg ceremony on the schedule despite all the fuss because Kohl asked for it as a favor," a senior U.S. diplomat said. "The least they can do now is to let us make our own choice where the president will go."

The West German press has also voiced exasperation with the uproar over the presidential itinerary. The conservative Die Welt warned that a gesture of reconciliation is now running the risk of fomenting dangerous bitterness between the two sides.

The independent Suedeutsche Zeitung said in an emotional editorial, "The shame of having waged and carried on the most horrible of all wars, fighting for an unjust cause and for criminal goals, is something the Germans have to deal with. The same is true for the sorrow and tears, for the lives this nation had to give.

"Leave us Germans alone with it. Nobody will be able to overcome it in our place just by making a 'gesture.' No officially planned ceremony may absolve us from it."

West German officials say they could not understand why the White House initially turned down the Dachau visit. The Americans, meanwhile, say they were misled about the nature of the Bitburg military cemetery, with its 30 SS graves.

The SS, which served as Hitler's bodyguard, also carried out many of the most brutal atrocities committed by the Nazi regime. Reagan is still expected to lay a wreath at Bitburg on May 5. In his letter to Reagan disclosed yesterday, Kohl expressed understanding for the criticism of Jewish groups in the United States and reiterated his offer of a ceremony at a concentration camp site.

But he also reiterated his firm desire to make a joint appearance at the German military cemetery in order to symbolize the end of wartime enmity and the flowering of German-American friendship.

Bonn government officials say they were perplexed why Reagan initially considered a trip to Dachau inappropriate. The chancellor's staff had cited Dachau as a prospective site for a commemoration, realizing that Reagan would probably want to acknowledge the Holocaust at some point in his visit, if only for domestic political reasons.

Kohl's primary interest, chancellery officials said, was to demonstrate German reconciliation with the United States by staging a solemn ceremony at a cemetery for war dead, preferably of both nations. The idea was sown during Kohl's appearance last autumn with French President Francois Mitterrand at Verdun, France, where the two leaders honored soldiers from their two countries who fell in the same battlefield.

But American war dead were evacuated from German soil in World War II, and Bonn officials said the only alternative was a German military cemetery.

The burial ground at Bitburg was chosen largely because it was near a U.S. military base, where Reagan could also pay a visit to American troops. Bitburg is also considered one of the most friendly communities toward U.S. soldiers, and thus security was judged very sound.

U.S. diplomats said the Bonn government was specifically asked if any political embarrassment might be connected with the Bitburg cemetery and were reassured that there was none.

Deaver and members of the U.S. advance team visited the site in February and did not notice anything unsavory about the site. But snow then covered the ground, obscuring the SS troops' tombstones.

Last week, the Americans were informed by the West German government that the SS graves were indeed at Bitburg. A Bonn spokesman insisted that the SS troops buried there were most likely teen-agers who were pressed into service against their will at the end of the war. But examination of the tombstones showed that some of the SS troops were in their thirties when they died, such as private Walter Hones, who was 39 when he was buried there.