JERUSALEM (AP) _ Left-wing legislators accused the Israeli government Wednesday of risking U.S. aid for absorption of Soviet immigrants by erecting hundreds of trailer homes and apartments in the occupied territories.

But in Washington, the State Department said Israel has assured U.S. officials that no immigrants will be directed to settle in new housing projects planned for the occupied lands.

About 100,000 Israelis live among 1.7 million Palestinians in the West Bank and Gaza Strip, captured by Israel in the 1967 Middle East War. The United States objects to these settlements and considers them an obstacle to peace efforts.

Haim Oron of the socialist Mapam party said Housing Minister Ariel Sharon told Parliament's Finance Committee on Monday that 1,000 trailers and another 1,200 apartments would be go up in the West Bank and Gaza in the coming year.

Another 300 trailer homes have been moved into the disputed territories in the past year, Oron quoted Sharon as saying.

Oron said Sharon insisted the government was not steering Soviet immigrants to the occupied territories, in keeping with American conditions for $400 million in loan guarantees voted by Congress this year.

But Oron argued that a housing shortage in Israel could easily propel immigrants to the occupied territories.

''People go where there are apartments, whether they are immigrants or old- timers,'' Oron said.

''Sharon never said it was being built for immigrants, but I think he's putting the issue at risk, since the Americans are unequivocally against their money reaching the territories,'' Oron added.

A communique from Sharon's office said a total of 33,000 trailers were to be purchased over the next year but did not say where they would be parked.

Sharon's spokesman, Nimrod Granit, was not available at his office to comment.

Sharon, a former defense minister, has led the Jewish settlement effort in the occupied lands since 1977, when he first joined an Israeli Cabinet as agriculture minister.

Labor Party leader Shimon Peres has also accused the government of indirectly pushing immigrants to move to the occupied territories by moving trailers there.

''Once the trailers are built there, they will say: 'We have no choice, the immigrants have no place to live,' and they will be forced to move there,'' Peres was quoted as telling a party forum on Dec. 13.

In Washington, State Department deputy spokesman Richard Boucher on Wednesday said Israeli authorities have provided assurances that they ''are not going to direct immigrants from the Soviet Union beyond the green line'' - Israel's internationally recognized border until 1967.

He also reaffirmed U.S. opposition to Israel's policy of establishing settlements in the territories, calling the activity an ''obstacle to peace.''

Soviet immigration has totaled more than 170,000 this year, and construction of housing in Israel has fallen far short of demand.

Israeli reports say construction is under way on less than half of 45,000 apartments planned for this year.

They said Sharon promised the committee that all would be in the building process by the end of the fiscal year in April.

Meantime, immigrant families are doubling up in apartments in some Israeli towns. Many arriving in the past month have been put up temporarily in hotels and army bases.