Soviet leader Mikhail Gorbachev told U.S. Commerce Secretary Malcolm Baldrige today that it was "high time to defrost the potential of Soviet-American cooperation."

During a 2 1/4-hour meeting at the Kremlin, Gorbachev complained that the United States was using trade as a political weapon against the Soviet Union and said that improved business ties depended on the restoration of "mutual trust."

According to the Soviet news agency Tass, Baldrige gave Gorbachev a letter from President Reagan expressing "in general terms" the wish for expanded U.S.-Soviet trade ties.

Baldrige is in Moscow to open the first high-level U.S.-Soviet trade talks since 1978. According to camera crews present at the start of today's meeting, Gorbachev welcomed Baldrige by saying it had been a long time since a U.S. commerce secretary had been to visit.

A statement issued late tonight by the U.S. delegation said Baldrige "expressed the view that no fundamental change in trade relations could take place without parallel improvements in other aspects of the relations."

The U.S. statement said Baldrige presented a different view on the causes of the deterioriation in U.S.-Soviet trade than those presented by the Soviet side. It said Baldrige pointed to "practical steps" to improve trade, but a spokesman would not elaborate.

In Washington, administration officials said Baldrige had no authority to permit Soviet purchases in two areas in which Moscow was most interested in expanding trade: strategic materials, including high technology that has military as well as civilian uses; and technology and equipment for oil and gas exploration, drilling and transportation.

The Soviets were most interested in buying U.S. technology, sources said, although in the oil and gas field they likely would have settled for state-of-the-art equipment.

The issue of selling the Soviets oil drilling and exploration equipment was hotly debated within the administration, according to the sources, with the Pentagon succeeding in preventing Baldrige from opening any substantial new areas of trade with Moscow on this trip.

Defense Secretary Caspar W. Weinberger, however, reportedly lost a last-minute bid to have Baldrige's visit to Moscow canceled. After the National Security Council approved the trip in an unusual Saturday session two weeks ago, Weinberger reportedly directed an unsuccessful appeal to President Reagan.

Baldrige also met privately today with veteran Soviet Foreign Trade Minister Nikolai Patolichev, before opening the first session of the U.S.-Soviet Joint Commercial Commission, a group founded in 1972.

The United States suspended meetings of the commission after the Soviet invasion of Afghanistan in 1979.

The decision last winter to resume the meetings, given positive press here at the time, was taken as one signal of a possible improvement in overall U.S.-Soviet relations. It was followed by the joint decision in Geneva to start arms control talks after more than a year's hiatus.

But serious differences still exist in U.S.-Soviet economic relations, and it was not clear whether this week's meetings would have anything more than symbolic significance.

After a dramatic decrease following the U.S. grain embargo and other economic sanctions, trade between the two countries has improved lately.

But in nonagricultural areas, trade is still at a low ebb, and the Soviets particularly have made a point of saying publicly that U.S. political decisions, such as the embargo, have made American firms unreliable trading partners.

Reagan administration officials have said they are not able to consider any shift in so-called "strategic" trade, or in areas that would require legislation, such as granting the Soviet Union most-favored-nation trading status.

In a statement to the joint commission today, Foreign Trade Minister Patolichev complained of the "sharp disbalance" in U.S.-Soviet trade and blamed the Soviet Union's deficit on the fact it has not been granted most-favored-nation status, which cuts tariff costs.

To restore trust in U.S.-Soviet trade relations, Patolichev said, the Soviet Union needs "confidence that the signed contracts will be fulfilled in their entirety."