U.S. and Soviet teams monitoring compliance with the new medium-range missile treaty have found no violations of the pact so far, says Brig. Gen. Roland Lajoie, head of the American inspection contingent.

"There have been no difficulties," Lajoie told reporters at the Pentagon on Thursday. Lajoie, the chief of the U.S. On-Site Inspection Agency, headed a team on the first round of American on-site visits to the Soviet Union at the beginning of this month, and was expected to begin the second U.S. round over the weekend.Four Soviet teams of 10 people arrived Thursday evening aboard a special Ilyushin-62 at Dulles International Airport and were to begin their second round of inspections Friday or Saturday.

The sites the Soviets were expected to visit were a Martin Marietta Corp. plant near Baltimore; Cape Canaveral, Fla.; the Redstone Arsenal at Huntsville, Ala; Fort Sill, Okla.; and possibily the Longhorn Army Depot at Marshall, Texas.

Although U.S. and Soviet inspectors were a little wary at first, said Lajoie, the process has gone smoothly since President Reagan and Kremlin leader Mikhail S. Gorbachev exchanged articles of ratification in Moscow on June 1 and the Intermediate-range Nuclear Forces treaty went into effect.

During a 60-day period of "baseline inspections," the Soviets are visiting 30 sites in the United States and Western Europe, and Lajoie and his team are inspecting 133 sites in the Soviet Union and Eastern Europe, to determine the accuracy of data exchanged by the two sides.