MOSCOW (AP) _ Alexander Dubcek, the leader of Czechoslovakia's 1968 ''Prague Spring'' liberalization that was crushed by Soviet tanks, has appeared for the first time on Soviet TV and defended his reforms.

Clips of an interview with Dubcek, who is now retired and living in the Slovak capital Bratislava, were shown on the Leningrad television program ''Fifth Wheel'' on Monday. The Foreign Ministry commented on the program at a news briefing Friday.

The clips were taken for a documentary that filmmaker A. Ruderman is making.

Dubcek, describing for Ruderman the Aug. 21, 1968, invasion of his country by troops of the Soviet-led Warsaw Pact alliance, said, ''The army came and took the (Communist Party) Central Committee with tanks and guns. Of course that's a very sad recollection.''

Dubcek said he picked up his office telephone to call then-Soviet leader Leonid I. Brezhnev but was confronted by armed soldiers who ripped out the telephone wires.

One of several Czechoslovaks who had gathered outside the party headquarters was shot and fell to the sidewalk, he recalled.

Interspersed in the film were comments by Prague citizens who denounced the Warsaw Pact intervention that ousted Dubcek and installed a hard-line Communist regime.

Dubcek's comments were shown on Soviet television at a time when two other Warsaw Pact members, Hungary and Poland, are going much further than Czechoslovakia's reforms 21 years ago without Kremlin interference.

Czechoslovakia's conservative leadership has blocked the reform efforts championed by Soviet President Mikhail S. Gorbachev.

Dubcek said the 1968 reforms sought to create a society in which many different opinions could be expressed freely.

''Radio, television and the papers did not say just what the government wanted. There were other points of view, and some of them were extreme,'' he said. ''Pluralism was written into our program.''

Dubcek described how he and other Czechoslovak leaders were summoned to Moscow where he was stripped of the party's leadership in 1969 and subsequently ousted from the party.

Foreign Ministry spokesman Vadim Perfiliev told reporters Friday that Soviet officials did not know ahead of time about the ''Fifth Wheel'' program.

''It's quite evident that this interview you're talking about was not in any way authorized officially and this program was not known to the authorities before it was aired,'' he said.

''Appearances of such programs in an impromptu way provoke some surprise with us because important political issues are concerned,'' he added.

Ruderman said Dubcek had been reluctant to be interviewed because Czechoslovak authorities still do not approve of his views.