The military structure of the Warsaw Pact will be scrapped by April 1, but the Soviet Union plans to maintain bilateral defense treaties with its allies, a presidential spokesman said Tuesday.

"We expect some reaction from the NATO countries," Vitaly Ignatenko, spokesman for Soviet President Mikhail Gorbachev, said without elaborating. Czechoslovakian officials said Monday in Prague that President Vaclav Havel had received a letter from Gorbachev agreeing to dissolve the Kremlin-led pact. They said pact officials were to meet in Budapest, Hungary, on Feb. 25 to formalize the bloc's action.Soviet officials have been calling for the transformation of the Warsaw Pact and the North Atlantic Treaty Organization from military into political organizations since the collapse of communist regimes in Poland, East Germany, Hungary and Czechoslovakia in 1989.

"Our countries came to the conclusion to dismantle the military structure of the Warsaw Pact and to finish this process by April 1," Ignatenko told a briefing in Moscow.

"We hope this will reduce military confrontation," he said, adding that the Soviets expect to continue some form of defense treaties with the individual pact members.

The Warsaw Pact was formed in 1955 in response to the creation of NATO. The original members were the Soviet Union, Poland, East Germany, Hungary, Czechoslovakia, Bulgaria, Romania and Albania. Albania left the pact in 1962.

Czechoslovakia and Hungary - both invaded at one time by Soviet-led pact forces to crush reform movements - have for months sought dissolution of the pact's military structures by June and abolition of the alliance early next year.