President Carter last night asked all Americans to stand with him during the crises in Iran and Afghanistan and said he would use "whatever action is required" to preserve American interests.

Speaking before the White House Conference on Small Business, Carter said the United States "will continue to protect American interests and, if possible" -- Carter paused -- "preserve the peace."

Carter, deviating from his text, also said that he didn't expect the resumption of "normal trade relations" with the Soviets -- disrupted in response to the Afghan invasion -- any time soon, "even under the best of circumstances."

That statement drew a sustained ovation and cheers.

A senior White House official last night said the "president was under scoring the fact that the action of the invasion would have a long-term impact on the relationship."

In his address to the 2,000 small business delegates assembled at the Washington Hilton, Carter said that during the crises and disruption of commerce, small business may suffer, but so will other segments of society. At the same time he listed a number of programs initiated by his administration to help small business. (Details on page D9.)

The address last night was one of a few appearances by Carter since the crises began.

"This has not been as easy two months for any of us," Carter said. "But we have shown America will not give into terrorism or international intimidation, whatever its form or wherever it occurs."

"I have been very proud of the American people," he continued. "We have risen to the occasion as a united nation . . . Some of our actions directly involve you, who represent small business enterprise in our country. You have demonstrated your willingness to make a reasonable sacrifice for the security and well-being of the United States."

Carter noted that the gathering was the first major conference "since the two crises erupted." He added that when groups representing the conference return in two years to assess its progress, "I expect to be here to greet you."

Carter then leaped from the stage and shook hands with some of the delegates.