WASHINGTON (AP) _ The Reagan administration said Tuesday the Soviet Union was being ''disingenuous'' when it announced last week that it will not exceed the limits established under the SALT II treaty.

''It overlooks the fact that for several years the Soviets have violated and continue to violate some of the central provisions of SALT II,'' the Arms Control and Disarmament Agency said in a statement.

The Soviets made their announcement following U.S. deployment Nov. 28 of its 131st strategic bomber armed with cruise missiles, bringing the United States above the limits on strategic systems agreed to under SALT II.

A statement by the Soviet news agency Tass denounced the deployment as irresponsible, but said Moscow still believes there is an opportunity for ''stopping the dangerous course of events.''

The ACDA statement said the U.S. decision last May to end adherence to the SALT agreement was taken in direct response to Soviet violations.

''The U.S. government has repeatedly sought correction of Soviet noncompliance and gave the Soviets over a year and a half to correct that situation. They failed to take the necessary steps to do so,'' ACDA said.

The statement added that U.S. strategic force decisions must be based on the threats posed by Soviet forces and not on standards contained in the SALT agreement that the Soviets have violated.

Among the alleged Soviet violations of SALT II, ACDA cited deployment of the SS-25 mobile ICBM, Soviet coding of missile test results, which prevents U.S. verification of treaty compliance and Moscow's decision to exceed the ceiling on strategic nuclear delivery vehicles.