The United States and the Soviet Union ended another two days of high-level negotiations yesterday still grapping with a few fisal obstacles to a new strategic arms limitation treaty (SALT) and pledging to continue efforts toward an early agreement.

Despite reports of some program, all indications were that another the ninth - round of negotiations between Secretary of State Cyrus R. Vande ndForeign Minister Andrel Groanyko will be necessary.

U.S. officials were unusually guarded is their comments peading a face-to-face report by Vance to President Carter, perhpas late today, and a possible White House announcement.

Gromyko, after nine hours of negotiations with Vance over two days, said the two sides are "a little closes" and "working hard" to reach an agreement. "The matter is very complicated" he said, and at another point suggested that he and Vance are going around in circled over a small number of contentious points.

A 60-minute meeting with Soviet leader Leonid Brexhnev in the Kremlin last night failed to resolve the outstanding issues.

A formal statement issued through Tass, the official Soviet news agency, called the meetings "useful and constructive" and said "stated the resolved to bend every effort and bring this important matter to a conclusion so as to ensure the early signing an agreement."

Despite the presence of Marshal Nikolai Ogarkov, deputy defense minister and chief of staff of Soviet forces, there was no indication that Brezhnev had put forth a new set of proposals to break the deadlock over the few unresolved issues.

U.S. sources said that the Soviet determination that a Carter-Brezhnev summit meeting should take place only when success of the negotiations is assured has not changed.

The final set of knotty issues in the 1972 SALT I negotiations was settled in intensive bargaining at the very top of the two governments during a visit by President Nixon to Moscow. With the next summit talks expected to take place in Washington - where Brezhnev and Gromyks would not have easy access to others in their major points would probably be impracticed.

The delicate conditions of Brezhnev's health may be another reason for Soviet insistence that the summit meeting should be for a signing ceremony rather than tough negotiations. A small group of American journalists permitted to witness the opening of the Brethnev-Vance meeting said the Soviet leader moved slowly and carefully, like an agining man, but with no special signs of acute problems.

Among the issues holding up the final agreement are ranging limitations on ground-and sea-launched cruise missiles, a matter of special importance to both NATO countries and the Soviet Union in the European threate, and the number of separate nuclear warheads that the United States will be permitted to place stop of its new generation of missiles, the MX.

After settling problems of tax greter strategic importance, the two sides seem to have dug in their heels.

Some type of extraordinary bargaining situation short of a summit meeting any be required to find a compromise formula.

Although the Vance-Gromyko talks steered clear of contentions issues in other fields, the session with Breahnev included discussion of several other subjects. The neutron bomb, the other subjects.The neutron bomb, the Middle East East and Africa are among the questions believed discussed.

The Soviet statement following the meeting said Brezhnev called attention to the "negative momentum" in Soviet-American relations in recent times. The statement said he stressed that the "ironing out of Sovet-American relations, ensuring their ascending development" would be in the best interests of the two countries, of international detente and of world peace.

The statement said the two aides have the "mutual intention" to facilitate progress on arms control for other nations and disarmament negotiations between them. Among those being worked on are a comprehensive nuclear test has treaty and an agreement on the sale of conventional arms.

The United States issued no statement, but spokesman Hodding Carter III said that it agreed with the main lines of the Soviet announcement.

Vance, in a luncheon toast, said that the two sides in the SALT negotiations cannot let themselves forget that "if we should fall in our efforts to regulate the strategic military competition, other problems would fade by comparison."

The proposed SALT II treaty would not bring any important measure of disarmanent or even stopt the arms race, but it is designed to impose a measure of control on the competition in strategic nuclear weapons and delivery systems.

According to State Department briefings given in connection with SALT, the United States now has about 10,000 nuclear warheads targeted on the Soviet Union, and the Soviet Union has about 5,000 nuclear warheads targeted on the United States.

The individual warheads on both aides, on an average, are several times as powerful as the atomic bombs which destroyed Hiroshima and Nagasaki, Japan, in August 1965.