President Reagan yesterday rejected the demands of Senate Majority Leader Robert J. Dole (R-Kan.) that defense spending in the next budget be trimmed further, saying it would be "very risky" and "we've squeezed that apple pretty good."

In a half-hour White House interview with seven radio correspondents, Reagan appeared to signal that he is unwilling to make additional concessions on defense spending as part of a possible compromise with Senate Republicans on the fiscal 1986 budget. But Reagan has in the past agreed to such a compromise after initially taking a rigid stance.

Dole said Friday that Reagan risks losing the domestic budget savings he wants unless the Pentagon compromises on defense spending. "I can tell you that unless we do more on the defense side, we aren't going to do much on Medicare, Medicaid or anything else," the senator said.

Defense Secretary Caspar W. Weinberger responded Friday by saying that those who want to reduce his budget want to weaken "the security of the country."

Yesterday, Reagan said the "shading" and "inflection" of Dole's remarks had been wrongly reported by "the printed media," and that the senator really was "calling attention to what could be a fact within the Congress," that "when they've needed money for some other program, they have thought, well, defense is the place we can get it."

Reagan said "what's being ignored" by congressional critics are "the cuts that the Defense Department has already made" in internal deliberations within the Executive Branch.

"Now, to go beyond that and just simply say, on a matter of dollars, 'We're going to take more dollars regardless,' is very risky, because the Defense Department -- that's the budget, the one budget that is dictated by people outside the United States," Reagan said.

Reagan also said that Weinberger already had produced more savings for next year than were sought by budget director David A. Stockman. Reagan did not mention, however, that he rejected a Stockman plan for deep cuts in defense spending authority in later years.

A freeze in defense spending for next year, as proposed by some senators, would shave $20 billion from the Pentagon budget. Weinberger has offered to cut about $9 billion. Stockman and others in the administration had been pushing for a compromise reduction in the range of $12 billion to $15 billion.

Reagan predicted yesterday that when the senators are told how much already has been trimmed from the Pentagon request, "I think they're going to see there isn't much more to get there." Reagan said he would put the defense budget "on the table" in negotiations with Congress, "but then we're actually going to show where the cuts are."

Reagan also said Congress is to blame for the huge deficits of his first term. "Every budget that we have submitted since I've been here has been smaller than the one that Congress would finally agree to," he said. "So, in fixing the blame for why we haven't done more than we've done in reducing spending seems to be pretty evident."

On another topic, Reagan urged the leaders of major black organizations, whom he has criticized, to shift the focus of their efforts. "And I think there is a need for us to focus more on what has been accomplished and less on creating an ill will and a feeling that all the grievances still remain," he said. "No, we haven't done the job completely. There is still further to go, but let's not forget what has been accomplished . . . . "

Reagan insisted that his longstanding political conflict with black leaders is due to a "lack of understanding or communication for some" blacks. "There is a black in our Cabinet and I had a meeting not too long ago with some 200 blacks in executive positions in our administration," he said. He also pointed to his support for enterprise zones, a subminimum wage for teen-agers and aid to historically black colleges.

On other subjects in the half-hour session, Reagan said he will make a state visit to West Germany after the economic summit in Bonn in May.

He also said the United States faces "an imminent threat of terrorism" and "our people worldwide have been targeted" by terrorists. But "one of the things that has kept us from retaliation" after terrorist bombings is "the difficulty in getting definite information" about the terrorists so innocent people are not killed in the retaliation.