The United States, looking to today's expected start of Lebanese-Israeli negotiations, stressed yesterday that it wants the talks to concentrate on a speedy agreement for withdrawal of Israeli forces and not become bogged down in efforts to force normalization of relations between the two countries.

In what appeared to be an oblique warning to Israel, State Department spokesman Alan Romberg reiterated the U.S. position that, while normalized relations are a desirable long-range goal, they must be achieved through consent of both governments and not through threats or pressures. In any case, Romberg said, such aims should not be allowed to interfere with achieving the fastest possible conclusion of agreement for withdrawal of all foreign forces from Lebanon, the establishment of Lebanese President Amin Gemayel's authority throughout the country and security arrangements that will protect Israel from cross-border attacks.

Achievement of these objectives is regarded as vital by the United States, both to defuse the potential for further military clashes between the many foreign and domestic factions in Lebanon and as a necessary step toward progress on President Reagan's broader goal of seeking to resolve the Arab-Israeli conflict through expanded negotiations over Israeli-occupied Arab territories.

In addition to the 30,000 Israeli troops that have been in southern Lebanon since Israel invaded last summer, the aim is also to achieve withdrawal of the roughly 35,000 Syrians and about 8,000 Palestine Liberation Organization guerrillas in the northern and eastern parts of the country.

Although Romberg did not say so specifically, his words appeared to be aimed at Israeli Prime Minister Menachem Begin, whose government has continued to insist that the talks will cover normalizing of relations and setting up a security zone in southern Lebanon to safeguard Israel's northern borders.

Since the evacuation of PLO fighters from Beirut in September, withdrawal talks have been stalled, in large part, by Israel's insistence first on negotiating a peace treaty with Lebanon and, after that demand was dropped, on winning from the Gemayel government some less explicit measure of recognition.

It was only after Reagan made clear his irritation at Israel and sent his special Mideast representative, Philip C. Habib, to the region with instructions to break the logjam that Israel abandoned its demand that talks be held in Jerusalem.

As of yesterday, both sides were continuing their posturing over what subjects will be discussed. But U.S. officials made clear that they expect the first meeting, planned for the Lebanese town of Khaldah outside Beirut, to go ahead on schedule today; they said that Reagan's special Lebanon mediator, Morris Draper, will take part in the meetings with the aim of keeping them on course toward the goals the United States considers most urgent.

In addition to problems caused by fencing over agenda and location for the talks, the United States is concerned that the Israelis want to leave some forces or use the security-zone arrangements as a device for maintaining de facto control over southern Lebanon. The Israelis are believed to be seeking a major role in that area for irregular Christian militia forces commanded by Saad Haddad, a cashiered Lebanese army major whose troops are armed and supported by Israel.

In the U.S. view, Haddad's continued ability to function as an autonomous warlord would undermine Gemayel's efforts to assert the central government's control over all of Lebanon.

During the Israeli-Lebanese talks, Draper will represent the United States, with Habib sitting in from time to time. Although Israeli Defense Minister Ariel Sharon warned Sunday against standing over the negotiations "with a stopwatch," U.S. officials stressed yesterday that the American representatives will seek the fastest possible progress. The United States will not be a direct participant in anticipated Lebanese talks with the Syrians and PLO about withdrawal of their forces.