Secretary of State Cyrus R. Vance met Soviet Foreign Minister Andrei A. Gromyko today to hear Moscow's reply to U.S. proposals for a negotiated settlement of the troops-in-Cuba dispute.

No details of the discussion were made public by either side. This was in keeping with the secretive pattern of the five previous U.S.-Soviet meetings on Washington's charges that a Soviet combat brigade is stationed in Cuba.

After the 75-minute meeting at the Soviet Mission here, the two ministers told reporters they will continue their talks at a previously scheduled session Thursday. "We touched the substance of some matters [but] we did not conclude," said Gromyko. Vance said they would be reporting to their respective presidents, Jimmy Carter and Leonid Brezhnev, before the Thursday meeting.

Pausing briefly before reporters as Gromyko escorted Vance to his limousine, the two men appeared solemn and tense -- a far cry from their last meeting in Vienna in June when their nations celebrated the signing of the strategic arms limitation treaty (SALT II).

U.S. proposals for settlement of the brigade dispute were transmitted only last Thursday through Soviet Ambassador Anatoliy F. Dobrynin. The swiftness of the reply and its delivery through the Soviet Union's most senior diplomat underscored the gravity of the problem, which has jeopardized Senate approval of SALT and threatens to damage over-all U.S. Soviet relations.

Word that Gromyko was ready to meet reached Vance just before he took the podium this morning at the United Nations General Assembly, where he warned in his annual policy address that "the East-West relationship can deteriorate dangerously whenever one side fails to respect the security interests of the other."

Asked how the "security interests" of the United States are affected by the Soviet brigade, State Department spokesman Hodding Carter said "nobody thinks they are going to invade the United States . . . "; they "do not represent a security threat." At the same time, he said broader U.S. security interests in the region are involved in the Soviet troops' presence.

President Carter told congressional leaders last Thursday morning that the U.S. objective in the negotiations is Soviet withdrawal of the combat brigade, but he also said such a definitive solution appears unlikely.The U.S. proposals passed to Moscow later the same day include measures for a solution short of full withdrawal.

Reported to be among these are ways to eliminate the Soviet "combat capability" by dissolution of the brigade, reassignment of key Soviet personnel to advisory duty and distribution of its tanks and artillery to Cuban forces.

On Capitol Hill today, Sen. Frank Church (D-Idaho), chairman of the Foreign Relations Committee, told committee colleagues that he plans to begin marking up SALT II next month, but would not report it to the full Senate until the Cuban issue is resolved.

Church, who has said the Soviet combat troops must be removed if the Senate is to approve SALT II, has discussed the possibility of approving the treaty with a reservation that it not go into effect until the president can certify that there are no Soviet combat troops in Cuba.

Vance, in his U.N. speech, suggested that the argument over the brigade is part of a mixed pattern of U.S.-Soviet relations in an era of far-reaching change. At the end of the decade of the 1970s, the said, "the unrelenting hostility of the cold war has given way to a more complex relationship between East and West, with elements of both competition and cooperation."

He declared that "the simple notion of a bipolar world has become obsolete. Increasingly there is a profusion of different systems and allegiances, and a diffusion of political and economic power."

Much of his speech dealt with the "North-South" issues of interest to the developing countries which make up the great majority in the U.N. General Assembly.

Vance expressed U.S. concern about the economic, energy and food problems facing the world's poor countries and proposed establishing a goal that by the year 2000 "no person on this bountiful earth should have to go hungry." He said the United States will do all it can to prevent the development of a global food crisis, but he voiced only general suggestions about increased crop yields and lowered population growth.

Vance spent nearly 90 minutes this morning with King Hussein of Jordan in a discussion of the Middle East peace process. Officials said the meeting was "useful and cordial" but there was no indication that Hussein was ready to join the Israeli-Egyptian negotiations over the future of the West Bank of the Jordan River.

The secretary of state also discussed the situation in Southern Lebanon. He announced to the General Assembly that the United States is working toward the goal of "not only a cease-fire, but a broader truce" in the area and said that today's Israel-Syrian dogfight underscored the fragility of the present cease-fire.