WASHINGTON--The United States and the Soviet Union are approaching the bargaining stage in their discussions on Soviet troops in Cuba, President Carter told congressional leaders yesterday.

Carter told prominent Congressmen of both parties at an unannounced meeting that previous discussions with Soviet officials focused on a search for information rather than on efforts to resolve the controversy.

Prior to Carter's session with congressional leaders, many had assumed that talks between Secretary of State Cyrus R. Vance and Soviet Ambassador Anatoly Dobrinin had been substantive.

Vance and Dobrinin met yesterday for the fifth time. They were reported to be arranging direct talks in New York next week between Vance and Soviet Foreign Minister Andrei Gromyko.

An authoritative administration official who provided an account of the president's early morning conference said new discussions with the Russians will aim at results that would "alter the situation" in Cuba.

The presence of the Soviet brigade of 2000 to 3000 men in Cuba has endangered Senate ratification of the SALT II strategic arms treaty with the Russians.

The administration source said that so far the talks between American and Russian officials assessed American intelligence data. The source added that the Americans asked the Soviets "a series of very specific questions" which were relayed to Moscow by Dobrynin and considered "at a very high level" there.

Sen. Howard Baker (R-Tenn.) who is seeking the Republican presidential nomination, said yesterday after the White House session that the presence of Soviet troops in Cuba is a "provocation." "I think the matter ought to have been dealt with by now," he added.

Sen. Frank Church (D-Idaho), chairman of the Senate Foreign Relations Committee, predicted that eventually "the Senate will require certification by the president that Soviet combat forces are not in Cuba."