U.S. officials said they had reached a "good understanding" about avoiding future incidents between Israeli soldiers and Marines at a meeting today involving U.S. Middle East envoy Morris Draper and the military commanders of the two forces.

It was understood that the Israeli area commander, Maj. Gen. Amir Drori, and his aides pledged that their troops would no longer try to pass Marine checkpoints and they would not fire in the direction of Marine positions during reconnaissance operations.

U.S. and Israeli officials concluded their 90-minute meeting without agreement on the boundaries of the two forces' adjacent zones of operation. But it was understood that there was common accord on trying to avoid repetition of several incidents that had brought strong expressions of concern from American officials, including Secretary of Defense Caspar W. Weinberger.

The problems were "resolved within a framework of irresolution," said one source familiar with the discussions today.

Americans here have worked assiduously to avoid any appearance that the Marines in the multinational peace-keeping force are coordinating activities with the Israeli forces occupying Lebanon and this has clearly nettled the Israelis.

Although Marine commander Col. Tom Stokes was present at the meeting today, the U.S. Embassy statement stressed the meeting was between Drori and Draper and Stokes was present only to assist Draper on "technical aspects"--a distinction clearly designed to refute press reports from Jerusalem that the two military commanders were getting together for a chat.

Israelis have claimed that Marines are harboring terrorists who attack Israeli convoys. Americans here have suggested privately the Israelis may be making that claim so that they can later argue that the international force cannot maintain security in Lebanon and thus there should be a long-term Israeli militiary presence here.

But beyond the accusations there is real concern on both sides about the security of their forces.

Israeli soldiers have increasingly been the target of attack and, in response, have taken a far more aggressive posture. Even support officers traveling through East Beirut have a soldier accompanying them with a rifle jutting out of the window.

Until earlier this week, Israeli troops had made a practice of "reconning by fire" along the main supply link between Israeli positions in the mountains and those southeast of Beirut. This sporadic firing of rifles and 50 mm machine guns near Marine positions had clearly worried U.S. officials.

Americans were also concerned about repeated attempts by Israeli patrols to penetrate Marine positions. In the last such incident 11 days ago, a Marine force was deployed into firing position when an Israeli patrol tried to enter the Marine-controlled area. The Israelis left after the Marine company commander spoke to them briefly.

Americans discount the Israeli allegations that terrorists are operating behind their positions.

In so doing, they emphasize first that the Marine mission here is not to root out terrorists but to provide a presence aimed at bolstering the weak Lebanese Army. They note that Lebanese authorities conducted extensive sweeps after the attacks on Israelis.