WARSAW, FEB. 3 -- Deputy Secretary of State John C. Whitehead said today that long-suspended U.S. economic aid to Poland would not be renewed until economic reforms here proved successful and the Polish government reached agreement on a stabilization program with the International Monetary Fund.

Following a four-day visit to Poland, Whitehead said there had been "considerable progress" in U.S.-Polish relations during the last year and that the Reagan administration looked favorably on a new program of economic restructuring launched by the government of Gen. Wojciech Jaruzelski.

But Whitehead said further improvements in the bilateral relationship would depend on more improvement in human rights here. He added that U.S. officials believed Poland's economic reform would not be workable unless Jaruzelski took steps to "win the support of a broad spectrum of Polish society."

Whitehead said the United States would consider extending new credits to Poland only "when and if {an} IMF agreement is concluded," under which Poland would commit itself to specific economic reforms. Approval from both Washington and the IMF, Whitehead said, would depend on "the initial effectiveness of the economic plan" launched by Jaruzelski late last year.

"We want to be helpful to Polish economic recovery," Whitehead said at a press conference today after a two-hour morning meeting with Jaruzelski. But, he said, "My sense, after my talks here, is that there is not yet an answer" on the question of forging the necessary political consensus, even though "that is the right question."

Whitehead's visit, part of a trip to four Warsaw Pact countries, marked a new step in the Reagan administration's year-old process of improving relations with Poland.

For Jaruzelski's government, the warming trend is particularly important because of its desperate need for western credits and investments. Cut off from almost all government and private loans for the last six years, Poland needs the funds to ease the burden of its $36 billion foreign debt and prop up staggering industries.

Government officials have opened negotiations with the IMF on a stabilization program and accompanying multi-billion dollar loan. But U.S. officials said that IMF approval for Poland's plans, and subsequent U.S. financial aid, were unlikely before the end of this year.

Such a delay could complicate Jaruzelski's economic efforts. But both Polish and U.S. officials sounded upbeat notes in describing Whitehead's visit.