WASHINGTON, April 17 (AFP) -

Israel sought in vain on Tuesday to prevent the United States from issuing a harsh denouncement of its move into autonomous Palestinian territory, diplomatic sources said here.

In a bid to preempt the release of a statement from Secretary of State Colin Powell that called the re-occupation an "excessive and disproportionate" response to Palestinian mortar attacks, the Israeli embassy notified US officials that a withdrawal was imminent, the sources said.

"The Israelis called the State Department and said they were going to withdraw from Gaza and to please not go ahead with the statement," said one source familiar with the exchange.

The call came well before the actual withdrawal began but shortly before State Department spokesman Richard Boucher read Powell's rebuke to reporters at his daily news briefing, the source said.

"The Israelis knew it was coming and tried to stop it," another source said. "It didn't work because (the United States) wanted people to know that Israel had crossed a red line when it went into Gaza."

The second source noted that Washington was intent on a strong statement because it had already been irked by Israel's cross-border air strike early Monday on a Syrian target in Lebanon in retaliation for a weekend attack by the Syrian-backed Hezbollah that killed an Israeli soldier.

"They had already crossed the Blue Line (the UN-established border between Israel and Lebanon) when they hit the Syrian radar, and now they had actually crossed a red line," the source said.

"The United States wanted Israel to hear a stern message about overreaction."

The Israeli army had moved into autonomous Palestinian territory in the Gaza Strip's Beit Hanun sector overnight in response to Palestinian mortar attacks and earlier Tuesday an Israeli general had told reporters the troops could remain there for "several months."

State Department officials declined to comment on any Israeli attempt to stop the Powell statement and refused to say whether they believed Powell's message or the threat of it had pushed Israel to withdraw so abruptly.

"Let's just say we're pleased to see it happening," said one senior official, recalling that Powell's statement had specifically called on Israel to withdraw from Gaza.

However, there were some indications the Israeli call to the State Department may have had some effect on the US statement, the final version of which officials said had had been toned down from early drafts.

Earlier drafts of the statement, which was written in consultation with the National Security Council, expanded on the steps Israel should take apart from withdrawing from Gaza, the officials said.

The changes were apparently made late -- around the time of the Israeli call -- as Boucher delayed the start of his briefing to check new language with higher ups, they said.