JERUSALEM, OCT. 1 -- The Israeli government announced today that it would begin distributing chemical warfare kits, including gas masks, to the general population to defend against a possible attack by Iraq.

Military officials said they had stockpiled enough gas masks and other equipment to supply all of Israel's 4.6 million citizens and visitors at a cost of at least $460 million in a distribution operation expected to last several weeks. However, they said they had not acquired masks for the 1.7 million Palestinians living in the occupied West Bank and Gaza Strip.

A military spokesman said the government had dispatched buyers to Europe to acquire more masks for the population in the occupied territories. However, officials said that while Israelis would be given masks free of charge, Palestinians who acquired them would have to pay for them.

The decision to distribute the kits followed weeks of debate within the government and military establishment over whether the move was warranted in view of the repeated threats by Iraqi President Saddam Hussein to attack Israel and to "burn" it with chemical arms. His latest version was that an attack could result should the current blockade become "strangling."

Israeli officials have expressed concern that distribution of the equipment might cause panic in Israel or be taken as a provocation by Saddam.

In making the announcement late today, senior government and military officials sought to reassure the public and Israel's neighbors with declarations that the distribution had been planned long before the Persian Gulf crisis and did not represent any change in the country's state of alert.

"It has nothing to do with the worsening of any situation or any change of the situation or any emergency," said Avi Pazner, a senior adviser to Prime Minister Yitzhak Shamir. "This is a precautionary measure that we are taking in light of the overall situation in the last few months in the area. We are going to proceed carefully and slowly and according to our plan."

Officials said Israel notified the Bush administration Sunday night of its intention to announce the distribution and held up the news until late today to allow for any reaction by Washington. They said there had been no sign of U.S. objections.

In a briefing for reporters, a senior military spokesman said that while the Army had decided in principle to distribute gas masks to the general population about six months ago, plans for the operation were speeded up because of the crisis and Saddam's threats against Israel. Mass distribution is to begin around Oct. 15, he said.

In addition to a mask, which comes in two sizes, the kits include an injection of atropine, which is an antidote to chemical warfare agents, and a powder to counteract liquid chemicals. The value of each of the kits, which were manufactured in Israel, is about $100, the spokesman said. It was not announced how much the Palestinians would be charged.

Military officials told Israelis tonight that they should not open their chemical kits but simply store them. Only in the event an attack appears imminent, officials said, will instructions be broadcast on how to open and use the kits. The military has devised a special new public siren to signal a chemical warfare alert and will test it in the near future, officials said.

Military strategists here say Israel probably would have advance notice of any attack by Iraq. Although Iraq has missiles capable of reaching Israel in a matter of minutes, and claims to have the ability to equip them with chemical warheads, intelligence analysts here say it would take the Iraqis up to 24 hours to deploy, arm and fuel missiles at launch sites in the western Iraqi desert.

Most Israeli analysts continue to say that an attack by Iraq on Israel with chemical or nonconventional weapons is unlikely. Such a strike, they say, would be unlikely to cause major casualties and would invite a devastating response by Israel, which is widely believed to possess both chemical and nuclear arms.