WARSAW, DEC. 9 -- The Soviet Union's Warsaw Pact allies in East Europe expressed jubilation today at the signing of a U.S.-Soviet treaty on intermediate-range missiles and offered cautious optimism about future accords on strategic arms.

However, some commentaries published in the state press here and around the region warned against "euphoria" and said East-West relations had not yet returned to the detente of the 1970s.

In East Berlin, where Warsaw Pact leaders will meet with Soviet leader Mikhail Gorbachev on Friday for a briefing on the summit, the newspaper Junge Welt set the tone with a huge photograph of a small child and a banner headline reading: "To the new millenium without nuclear weapons."

East German communist leader Erich Honecker, who along with the Czechoslovak communist leadership faced strong public discontent when Soviet SS20 missiles were deployed in the two countries in 1984, hailed the pact and declared, "We have never disguised that the stationing of additional nuclear weapons in East and West brought us no joy."

In Poland, the newspaper Dziennik Ludowy carried a headline proclaiming yesterday's signing ceremony as "the best 270 seconds since V-E Day" -- a reference to the day World War II ended in Europe.

"We all received this solemn, historic moment with deep relief," said the paper's commentary, adding that "the summit document signed on Tuesday is the triumph of actions termed as the 'new way of thinking' in the Soviet Union."

Several other East European commentaries pointed to Gorbachev's innovative leadership as the key factor in the success of the negotiations.

Hungary's communist daily Nepszabadsag pointed out that when the idea of eliminating all intermediate-range missiles was first suggested by President Reagan, nobody had believed it could be achieved. However, it said, the rise of Gorbachev had made possible a change in Soviet policy and, eventually, acceptance of the agreement.

Some commentaries in the Polish state press pointedly cautioned against excessive optimism about East-West relations in the wake of the arms agreement.

The Army daily Zolnierz Wolnosci said that the treaty "does not yet signify either the return to the era of detente or the full normalization of relations."