President Reagan yesterday called the federal bureaucracy a "growing administrative monster" and announced plans to overhaul it by 1988 and save the equivalent of $2,000 for each American family over a six-year period.

Renewing his 1980 campaign attacks on "fraud, waste and abuse," Reagan said he will call his senior appointees to the White House to launch "Reform '88," a six-year effort "to upgrade management of the federal government."

The president also signed a $7 billion supplemental appropriations bill passed by Congress Friday night to cover federal expenditures for the remainder of the 1983 fiscal year. It includes $1.2 billion to continue food stamp payments and $25 million in added military assistance to El Salvador.

Meanwhile, the president said in a television interview (the McLaughlin Group, WRC-TV) taped Friday that he does not believe there is a thaw "yet" in relations with the Soviet Union, despite the recent U.S.-Soviet grain deal.

"But what we're trying to indicate to them," he said, "is that...if they'd straighten up and get out of Afghanistan, and some things--in other words, just as I said about Castro--if they would look at the world and decide that they wanted to get along with their neighbors instead of living as an armed camp and threat against all of us, they could have a lot better living than they're having."

Reagan told the interviewers that the United States is not ready to lift sanctions against Poland because "we want to see that the actual lot of the Polish people has improved and that they're not living under tyranny just under a different definition."

He also said that after meeting last week with the Israeli defense and foreign ministers he is convinced that redeployment of Israeli troops in Lebanon is "no major problem at all. In fact it's welcome."

Reagan criticized former Mexican president Jose Lopez-Portillo, whom he called "churlish," for failing to accept terms of a loan from the International Monetary Fund before leaving office.

He also criticized the news media, blaming it for the American people's failure to "know which side we're on in El Salvador or Nicaragua."

In his regular Saturday radio speech, the president said from Camp David, Md., that since he took office the volume of new federal regulations has been cut by one-fourth, "the rapid rate of growth" in government spending has been reduced and the inspector general program has "saved or put to better use" $22 billion.

Referring to recent disclosures of overcharges for military spare parts, including "$916 plastic cap purchases," Reagan said that such "horror stories . . . are the result of our own investigations." He said that Defense Secretary Caspar W. Weinberger is seeing that negligent employes are fired and that irresponsible contractors are taken to court.

The president then announced his new effort to retool the federal administrative machinery. He said that the changes would save tens of billions of dollars.

"You may have heard about the individual who obtained 10 housing and urban development loans and defaulted on all 10. In the future, deadbeats like that will be headed off at the pass," said the former star of cowboy movies.

In the Democratic response to the president's speech Sen. Dennis DeConcini (Ariz.) said that he is glad Reagan is willing to deal with "waste, fraud and abuse that exists at almost every level of the federal government."

But DeConcini added, "I sincerely hope that the president will soon be prepared to make the same commitment to reduced deficit spending that he made today to reduced waste and fraud in government."