JOHNSTON, IOWA, JAN. 7 -- Vice President Bush said today he did not recall hearing objections by senior Cabinet members in 1986 to the secret Iran arms sales, and said the subject came up only briefly in his daily morning national security briefings with President Reagan.

The vice president's comments here came in response to questions about a report in The Washington Post today that Bush watched the arms sales unfold step-by-step and that he was more informed of details than he has acknowledged.

The report received wide attention in Iowa today, site of the first caucuses of the 1988 presidential campaign next month. All of Bush's competitors for the Republican nomination were here or en route for one of the major events of the year, Friday's Des Moines Register debate.

Most swiftly seized on the issue, suggesting the vice president is not being forthcoming. Senate Minority Leader Robert J. Dole (Kan.) said the debate would likely feature questions on the issue and noted, "I think it would be in his interest and in the interest of all Republicans to tell us precisely what he knows." Rep. Jack Kemp (N.Y.) called on Bush to "clear the air."

Bush appeared eager to tackle the issue head-on by answering questions at some length during his first campaign stop this morning.

Standing in sub-freezing weather outside a farm research lab here, Bush asserted often that he was unaware of critical details and important facts about the Iran arms deals. Bush has previously said he was "deliberately excluded" from key meetings on the Iran initiative.

"It wasn't planning and discussing and going over all these details," Bush said of the morning sessions with the president. The Post report had cited a participant in regular meetings with the president who described Bush as being present at dozens of meetings where the Iran deals were discussed and as knowing basically as much about it as the president.

Asked today whether he knew as much as Reagan, Bush replied, "I knew a lot -- close to it -- but I don't know whether I knew everything."

Bush also said he did not know at the time that the United States was trading arms for hostages and that he did not recall any discussion of the critical Jan. 17, 1986, presidential "finding" that Reagan signed approving the deals.

Bush vowed once again not to reveal the advice he gave Reagan on the Iran arms deals, even if the president released him from his pledge of confidentiality in their discussions. But Bush did say that both he and Reagan were motivated by their desire to free Americans being held by extremist groups in Lebanon, and Bush added, as he has before, that he had "reservations" about using a "third country" in the operation. Bush did not mention Israel today but has previously said he worried that the United States was relying too much on Israel in the clandestine transactions.

Bush was asked today, for example, about a Jan. 7, 1986, meeting at which Secretary of State George P. Shultz and then-Secretary of Defense Caspar W. Weinberger voiced strong objections to the Iran arms sales. According to the report of the congressional Iran-contra committees, this was a "full" meeting of the National Security Council, which includes the president, vice president and top Cabinet members.

"I don't recall that," Bush said when asked if he had heard the Shultz and Weinberger objections. Contrary to the congressional report, Bush said there was "not a full NSC meeting on that date."

A former administration official said tonight that Bush may have missed the forceful objections by Shultz and Weinberger because he left the session before the secretaries spoke out that day. The official said this is shown in previously unpublished documents which he said were discovered because of questions over the vice president's role.

In another case, Bush was questioned about the Jan. 17, 1986, meeting at which then-national security adviser John M. Poindexter briefed Reagan with a revised "finding" or authorization for the secret arms sales, some of which had already taken place. The signed document was dated Jan. 17.

Bush was at the meeting, according to Poindexter's handwritten notation on a briefing paper. Bush said today, "I don't recall a finding being signed and I think I'd remember that. Now, the president may have signed the finding, but there was no discussion of a finding in front of me, because that's one I would remember from my CIA days.

"I do not recall any suggestion of a finding that day -- any," the vice president said.

In a third instance, Bush was asked about his July 29, 1986, meeting with Amiram Nir, then a counterterrorism adviser to former Israeli prime minister Shimon Peres. According to a memo written after the meeting by Bush's chief of staff, Craig Fuller, Nir discussed the timing of arms shipments and the release of the hostages.

Asked today if he had any sense of the arms-for-hostages nature of the transactions at that meeting, Bush said, "No, I did not. I sensed that we were sending arms. And I sensed that we were trying to get hostages out. But not arms for hostages."

Bush said he only learned later, after the arms deals were disclosed, that they had been a swap of arms for hostages. "It's only when it became clear that it was arms for hostages with the benefit of hindsight that you say, yeah, that was wrong," Bush said.

The vice president said he did not get "full disclosure" about the Iran deals until he was briefed in December 1986 by Sen. David F. Durenberger (R-Minn.), then chairman of the Select Committee on Intelligence.

The congressional report pointed out, however, that there were many documents and meetings during 1986 in which the arms-for-hostages nature of the deals was made explicit.

In another case, Bush was asked about his reaction when Poindexter and Lt. Col. Oliver L. North suggested to Fuller in November 1986 that the vice president should make a trip to the Middle East to explain the Iran arms sales. "I don't recall being asked to do that," Bush said. Asked if he was aware of the query to Fuller, the vice president said, "I don't recall being asked to go to the Middle East by Col. North or anyone else in November 1986."

Bush was questioned if he "began to smell a rat" during the Iran affair, from its inception in 1985 through its disclosure in November 1986. "Not really, no," Bush said.

On the subject of his morning meetings with the president, Bush said they were not detailed discussions of the Iran initiative.

"Let me tell you how it works," Bush said. "Somebody comes in there like Don Regan, me, the president. 'Did you hear anything new on the hostages today? Got anything new on that?' 'Has it moved forward at all?' We'll ask Poindexter. Poindexter would come into the room. 'No, we haven't had a report.' That's the end of that meeting. Then you go on and talk about the budget and talk about something else."

The vice president put an added emphasis today on concern that he said he shared with Reagan for the plight of hostages held in Lebanon.

"If we erred, the president and I, and others who supported it erred, it was on the side of human life," Bush said, recalling his concern when the Central Intelligence Agency's Beirut station chief, William Buckley, was brutally tortured and murdered.

Bush also asserted he had done nothing illegal and was not a target of the investigation by Independent Counsel Lawrence E. Walsh. The vice president said he would cooperate with Walsh and has said he expects to be interviewed by Walsh next week.