United Nations, N.Y. — Diplomats and UN officials are working frantically this week to try to stitch together a group of neutral observers to supervise the cease-fire in Lebanon. Their efforts are bogged down. There seems to be little room for compromise, given the gaps between US and Soviet objectives on the one hand, and of Syria and of Lebanese President Amin Gemayel on the other.
Syria's Foreign Minister Abdel Khalim Khaddam holds the trump cards to the ongoing negotiations, and it appears the Syrians are not immediately interested in having UN observers supervise the cease-fire.
Meanwhile, US Secretary of State George Shultz has met with the foreign ministers of France, Italy, and Britain and is scheduled to meet with Mr. Khaddam on Friday. The French, Italian, and British foreign ministers met with UN Secretary-General Javier Perez de Cuellar. The Secretary-General also met with the Syrian and Lebanese foreign ministers.
Despite appearances to the contrary, the US and its three partners (France, Italy, and Britain) in the multinational force in Lebanon do not see eye to eye as far as their role is concerned and as far as what they hope to achieve, according to a high-ranking Western diplomat.
Nor is there complete harmony between the US government and the Lebanese President. Or for that matter between Syria's President Hafez Assad and the Kremlin. The Syrian and Lebanese governments also are in opposition with regard to the cease-fire's real purpose, according to the same source.
Talks with a dozen diplomats involved in the negotiations have made clear that:
* France, Italy, and the United Kingdom insist that their presence in Lebanon is independent from that of the US. France in particular does not want to be seen as doing ''Israel's dirty work'' in Lebanon, and is not ''out to get Syria'' or to ''impose a Christian peace on Lebanon's Muslims,'' as one well-placed diplomat puts it.
The three European nations are opposed to the de facto partition of Lebanon and are pushing strongly for a United Nations-affiliated group of observers to supervise the cease-fire. They have asked Mr. Perez de Cuellar to inform the president of the Security Council that he wishes to enlarge UNTSO (UN Truce Supervision Organization, founded in 1948), and send perhaps 500 or 600 of its members to police the cease-fire lines.
Perez de Cuellar has moved cautiously and sounded out the Soviets on the matter. So far their response has not been encouraging, according to sources.
* The US wants to restore Lebanon government authority over its whole territory and to preserve Lebanon's territorial integrity. It is mindful not to cross Israel in any way, diplomatically or militarily. It may also want to keep a military foothold in Lebanon for strategic purposes, though this is not officially spelled out.
* Syria moves prudently. On the one hand the Syrians want to avoid further confrontation with American forces and do not want to give Israel an excuse to start a war. On the other hand the Syrians want to keep their options open in Lebanon and do not want to tie their hands.
By allowing a UN force to supervise the truce, Syria's own future possible military initiatives might be hindered as might those of Syria's Lebanese proteges.
For Assad as well as for Gemayel, the truce is not an end in itself. What matters is the power play - through political and military means - that will determine who controls Lebanon.
Syria is believed to prefer that a new multinational force, not linked to the UN, composed of Yugoslavs, Indians, Norwegians, and others whose nationality it finds acceptable, supervise the cease-fire. But Yugoslavs and Indians are not eager to volunteer for such a force: ''Look at what happened to the Franco-Italo-British force,'' a nonaligned diplomat said.
* The Lebanese government ultimately wants both Syrian and Israeli troops out of Lebanon. But Israel is not about to pull its troops out of southern Lebanon and Syria is known to feel that Lebanon is but a province of Syria and that ''Syrian troops in Lebanon are not really in a foreign country.''