Secretary of Commerce William Verity arrived Monday on a mission to boost U.S.-Soviet trade but warned that any increase would depend on improvements in other parts of the superpower relationship.

Verity arrived as the U.S. firm Honeywell Inc. announced it had set up a joint venture with the Soviet Ministry of Mineral Fertilizer to help modernize fertilizer plants by installing Honeywell automation and control equipment."The U.S. government supports the expansion of peaceful, mutually beneficial trade and economic relations between the United States and the Soviet Union, and we hope to reach agreement on some specific steps that can expand our trade within current policies," said Verity, in Moscow to attend the annual session of the Joint U.S.-U.S.S.R. Commercial Commission.

"We are also here to explain our view of the role that trade plays in the overall relationship between the United States and the Soviet Union, and our view that fundamental gains in the trade relationship depend upon improvements elsewhere in our relations," he said.

The commission is meeting in an effort to improve the current low level of trade between the countries. The U.S. delegation includes 500 business executives.

The United States through the Jackson-Vanik Amendment to the 1974 Trade Act prohibits extension of U.S. government credits and most favored nation status to any communist country that restricts free emigration of its citizens. The amendment sponsored by Sen. Henry Jackson, D-Wash., and Rep. Charles Vanik, D-Ohio, was prompted by U.S. concern over the Soviet Union's treatment of its Jewish population.

The difficulties in business relations, as well as the successes, were illustrated by the Honeywell announcement of a joint venture after 10 months of sometimes difficult negotiations. It was described as only the third U.S.-Soviet partnership in the 15 months since Moscow enacted joint venture legislation.

Honeywell, a company with sales last year of $6.68 billion, is investing about $1 million in a technical center for engineering, training and marketing industrial process control systems.

Feasibility studies for manufacturing instruments would begin immediately after the official signing of the joint venture documents Thursday.