NEW YORK -- Several American Jewish groups are organizing visits to Israel and planning to hold meetings there as an expression of solidarity and to show tourists that it is safe to travel to the country.

The Israeli Tourism Ministry has reported that tourism from the United States dropped 22 percent in September and 46 percent in October compared with the same months in 1989. The declining figures have resulted in layoffs of 2,000 hotel employees.

According to the Tourism Ministry, the October total of 57,000 tourists made it the worst October for tourism since 1973, when tourists were banned during the Yom Kippur War.

Several factors have been cited as reasons for the decline, including the Israeli army's decision to distribute gas masks to the entire population and a U.S. State Department advisory against travel in the Middle East.

Both developments have resulted from the Persian Gulf crisis and the possibility that Israel could become involved in a war against Iraq.

The drop in tourism has led the Tourism Ministry and El Al, the national airline, to suspend international advertising campaigns on the ground that the money would be wasted. But American Jewish groups have sprung into action on several fronts to try to reverse the trend.

The American Jewish Congress, which says it operates the largest Jewish travel program in the world, has announced plans for a Hanukah Solidarity Mission to Israel. Henry Siegman, the organization's executive director, recently received an award

from the Ministry of Tourism for taking the 300,000th visitor to Israel in the American Jewish Congress program.

The American Jewish Committee is taking 100 of its leaders from 15 U.S. cities to Israel in a mission titled "Operation Undaunted." Participants will meet with Prime Minister Yitzhak Shamir and other government officials and several prominent Israeli Arabs. "We are concerned about the impact of tensions and isolation on the Israeli people and wish to emphasize our solidarity with the people through our presence," said Lawrence Thorpe, of Atlanta, who is leading the mission.

The 20 regions of the United Synagogue of America, the association of Conservative congregations, is organizing trips to Israel. "Now is the time to stand up and be counted," said Alan Tichnor, president of United Synagogue. "We must use every possible opportunity to express our support for our brothers and sisters in Israel during these trying times."

Seven leaders of the MetroWest Jewish community in New Jersey canceled business appointments and personal plans this month to fly to Israel for a week. James Schwarz, past president of the United Jewish Federation of MetroWest, said the trip was designed to demonstrate to the Jewish community at large that "travel to Israel is safe."

Hadassah, the women's Zionist organization, has shifted the site of its midwinter national board meeting, scheduled for Jan. 27 to Feb. 2, from Washington to Jerusalem.

"In this time of crisis for Israel, when her people feel isolated and even abandoned, we want to express our Zionist principles through action," said Carmela Kalmanson, Hadassah's national president.