WASHINGTON--President Reagan refused to answer questions yesterday about the Iran-Contra scandal, while Defense Secretary Casper W. Weinberger '38 said the administration had secretly provided intelligence information to both sides in the Iran-Iraq war.

Reagan maintained his two and one-half month silence while Robert Gates was undergoing a second, tough day of questioning at his Senate confirmation hearing to take over as CIA director. Elsewhere in Congress, the Democratic-controlled Senate Foreign Relations Committee voted narrowly to cut off further aid to the Contra rebels fighting the Nicaraguan government.

Reagan seemed in no mood to field questions on the controversy when reporters were permitted into the Oval Office before his meeting with Israeli Prime Minister Yitzhak Shamir.

"I'm not going to take any questions on that situation" until after a presidential commission files its report on the Iran-Contra affair on February 26, Reagan said. He refused to elaborate on his previous comment that mistakes had been made and declined to identify who had been guilty of the errors.

Reagan has consistently defended his decision to sell arms to the Iranians, and said he knew nothing of the apparent diversion of profits to the Contras until Attorney General Edwin Meese III unearthed evidence of its last November.

For his part, Shamir left the White House and later traveled to the Capitol, where he agreed to meet briefly with Sen. Daniel Inouye (D-Hi.) and Rep. Lee Hamilton (D-Ind.), chairmen of the two congressional committees investigating the controversy.

Israelis played a major role in facilitating the sale of weapons to the Iranians, according to previous investigations, but their role in funneling funds to the Contras is less clear. Inouye and Hamilton sought the meeting with Shamir as an administration official said the president had privately sought Israeli cooperation with the various investigations.

Weinberger, testifying before the House Foreign Affairs Committee, defended his decision not to notify Congress about the transfer of arms to Iran. He said he had no obligation to do so because the only role the Pentagon played in the transfer was to provide the weapons to the CIA.

Several members of Congress have charged that by withholding word of the secret sale from the House and Senate for more than 10 months, the Reagan administration violated the law requiring timely notification of covert activity.

Weinberger confirmed previous statements from Secretary of State George Shultz that the United States had provided intelligence information to Iraq in its long war with the Iranians.

But where Shultz has previously denied knowledge of similar assistance to the Iranians, Weinberger said he was aware they had received intelligence information, as well.

"I am told later that at different times, at least one time, there was some intelligence furnished to the Iranians. And I have to confess that in many ways, I think that's one of the worst parts of it," Weinberger said.

While Weinberger was appearing before the House committee, CIA Director-designate Gates came under fire before the Senate Intelligence Committee.

Sen. Arlen Specter (R-Pa.) charged Gates with trying to evade responsibility for "skimpy, scanty and really misleading" testimony that he said former CIA boss William J. Casey presented to the committee last year.

Gates was deputy CIA director at the time, and Specter said, "You are trying to distance yourself from that testimony," He said Gates' explanation of his role as having directed preparation of Casey's testimony but not its details carried "a shade of dissembling."

In another development, the head of the General Accounting Office said his agency has prepared a classified report that traces the shipments of U.S. arms to Iran, and expects to present its findings next month to congressional committees. Comptroller General Charles A. Bowsher said the GAO also had begun an effort to trace the flow of arms sales profits to the Contras in Nicaragua.