The official Soviet news agency Tass accused the director of the Arms Control and Disarmament Agency today of "falsifying facts" about U.S. adherence to the 1979 SALT II treaty and of seeking to force the Kremlin to abandon its "principled" opposition to the Reagan administration's "Star Wars" search for a missile defense.

The Tass report, by military analyst Vladimir Bogachyov, said that under Director Kenneth L. Adelman, the arms control agency has been "preoccupied with compiling falsehoods for Congress and the press" and "has become a propaganda affiliate of the Pentagon."

The report charged Adelman with masking U.S. violations of SALT II during a news conference with foreign journalists. Adelman said that Washington continues to abide by the treaty, according to Tass.

"Such statements . . . give rise to perplexity," Tass said, charging that the U.S. Midgetman and MX missile projects violate the treaty. The Midgetman, it said, "is in no uncertain terms forbidden" by SALT II.

Tass defended the Soviet RS12 missile reportedly mentioned by Adelman as a new type that would balance out any new American intercontinential ballistic system. The characteristics of the missile, Tass said, are in full accord "with the respective provisions of SALT II."

In a speech Wednesday, Soviet leader Mikhail Gorbachev called on the Soviet Union and the United States to adhere to the provisions of the treaty, which was signed by both countries during a 1979 summit meeting.

The U.S. Senate failed to ratify the treaty following the Soviet invasion of Afghanistan, but both countries assert that they comply with its provisions.

The unratified treaty would expire this year. "Since the beginning of the '80s," Tass charged, the United States has been "gradually crawling out of the treaty." It said Adelman indicated that Washington would "manage to make the Soviet Union abandon its principled line toward preventing militarization of outer space." The idea, Tass added, is a "fantastic supposition."