The United States has accepted Israel's position that the planned partial pullback of its forces from Lebanon is only the first stage in the removal of all its troops from that country and that no date need be set for the next phase, Israeli officials said last night.

Foreign Minister Yitzhak Shamir and Defense Minister Moshe Arens spent seven hours yesterday convincing Secretary of State George P. Shultz and other senior U.S. officials that Israel had no intention of digging in and creating a de facto partition of Lebanon after the completion of the first withdrawal.

Shultz reportedly suggested to the Israelis that they set a date for the next phase of their pullout, but they argued, apparently successfully, that until Syria expressed readiness to remove its 50,000 troops from Lebanon, an Israeli timetable would serve no purpose.

The Americans will now inform the Lebanese, officials said, that there should be close cooperation between Washington, Jerusalem and Beirut in working out how the Israeli redeployment will affect the situation in Lebanon.

The Israelis were clearly anxious yesterday to fulfill U.S. hopes--expressed Tuesday by President Reagan--that their planned move was only a first phase in a total pullback to the international border.

Shamir told reporters after the talks: "We discussed all the problems connected to the redeployment of our forces and explained all our concepts about it as a first stage in the implementation of the agreement concluded between us and the Lebanese."

Robert C. McFarlane, who replaced Philip C. Habib as Reagan's special envoy last week, called the talks "good."

He told reporters that he would be leaving Friday on the first leg of a regional tour that is expected to include Syria, Lebanon, Saudi Arabia, Jordan, Egypt and Israel.

The State Department would not comment on the content or progress of yesterday's discussions, but Israeli officials described them as "friendly and businesslike."

The Israeli delegation, which includes their chief of military intelligence and the Defense Ministry's coordinator of activities in Lebanon, told the Americans that Israel was prepared to use its "good offices" to help settle conflicts between the Druze in the Shouf Mountains--one of the areas Israel plans to evacuate--and the Lebanese government of President Amin Gemayel.

On the U.S. side, Gen. Andrew Cooley, the officer in charge of training the Lebanese army, presented a progress report on Lebanese military capabilities, a crucial factor in any U.S.-Israeli coordination on the partial pullback.

Israeli officials described Cooley's report as "encouraging." One emerging problem, observers noted yesterday, is that the Israelis' insistence on close cooperation with the Lebanese may well prove embarrassing to Gemayel, who has been attacked by some Arab countries, notably Syria, for signing the agreement with the Israelis last May.

Syria, meanwhile, underlined its opposition to U.S. policy in the region by attacking Reagan for saying that it had set up a "roadblock" to efforts to secure withdrawal of all foreign forces from Lebanon.

The state-run Damascus Radio said "this accusation does not help the United States carry out the role it wants for itself, nor does it make a successful prelude to the mission of the new American envoy to the Middle East."