No definite plans have been made for an expected visit to the Soviet Union by Defense Secretary Dick Cheney because the Soviets haven't suggested a date, the Pentagon spokesman said Tuesday. At the end of an October tour of U.S. military facilities, Defense Minister Dimitri Yazov invited Cheney to visit the Soviet Union. There have been ongoing exchanges in recent years between the two nations' military and defense leaders. The trip was expected to occur sometime this summer, but no date has been announced. Last month, the Bush administration called off a scheduled visit to the Soviet Union by Army Chief of Staff Gen. Carl Vuono, calling the trip inappropriate amid the tensions over Lithuania. Pentagon spokesman Pete Williams, queried at a briefing about Cheney's invitation, told reporters that no firm date had been offered by the Soviets and that there were no plans for Cheney make such a trip ``on the near horizon.'' However, Williams added, ``We are eager to do so.'' Besides meeting with Cheney at the Pentagon, Yazov visited Camp Pendleton, a Marine training base north of San Diego; Luke Air Force Base in Arizona; and Fort Bragg, home of the Army's 82nd Airborne in Fayetteville, N.C.