President Reagan said yesterday that Soviet leader Mikhail Gorbachev had expressed a willingness in their summit talks last week to withhold aid from the Sandinista government of Nicaragua except for "some small arms, police-type weapons."

Speaking to reporters at a brief picture-taking session, Reagan was asked what he told Gorbachev in response to the offer. He did not answer the question, but looked at a note card and said, "This is a subject we are going to be discussing for quite some time."

"All I know is that Gorbachev told me he wanted to go forward with the peace plan and he would withhold aid from the Sandinistas," the president said. Gorbachev mentioned "all military aid," Reagan added.

Reagan's comments yesterday did not clarify precisely what the Soviet leader might have intended in a brief discussion of Nicaragua with the president last Thursday, a few hours before the three-day summit ended. U.S. officials are attempting to have the Soviets clarify Gorbachev's comments.

Meanwhile, administration officials expressed continued confidence yesterday that Congress will approve a controversial request for new aid to the Nicaraguan contras.

In the House, where there is strong Democratic sentiment against more contra aid, officials conceded yesterday that there is considerable momentum to approve some new assistance as part of an omnibus spending bill that the House and Senate are attempting to finish by the end of this week.

The Senate version of the bill, which was passed early Saturday, includes an additional $9 million in nonlethal aid, plus an unspecified amount -- estimated by the administration to be between $6 million and $7 million -- to cover transportation, including continued air drops inside Nicaragua. The money is intended to support the contras through February. The House version includes no new contra aid.

House Democratic opposition is making a compromise with the Senate difficult and could threaten adoption of the overall spending bill, the continuing resolution, congressional aides said yesterday.

Rep. David R. Obey (D-Wis.), a leading House negotiator on the contra issue, said yesterday that "the main question is whether {the spending bill} can pass the House if it has any further aid to the contras."

"We are not going to accept any more military aid," Obey said, "and many of the members don't want any aid at all."

Obey said the Senate bill contains language that amounts to "a substantial military loophole." For example, House Democratic aides said the Senate version would include transportation funds to permit delivery inside Nicaragua of stockpiled lethal aid, such as bullets and weapons, along with medical supplies, clothing and other nonlethal aid.

The Senate bill would also enable the Central Intelligence Agency, which has the main responsibility for managing the contra program, to purchase or lease new helicopters and planes to help deliver the aid, according to congressional aides and administration officials.

Administration officials have argued that some of the ferry aircraft must be replaced.

However, some House Democrats strongly oppose lethal aid drops and the purchase of new aircraft. They argue that continued U.S. military aid to the contras would be contrary to the regional peace process now under way in Central America and would provide the Sandinista government with an excuse not to comply.

House Democrats also dispute administration estimates on how much additional nonlethal aid is needed to sustain the contras.

A source close to the House and Senate negotiators said yesterday that the House is likely to go along with about $5 million in new nonlethal aid, but not funds for transportation or lethal aid air drops.

Administration officials expressed confidence yesterday that they will prevail on Capitol Hill, particularly in light of the disclosure of a planned Soviet arms buildup in Nicaragua. Maj. Roger Miranda Bengoechea, a Sandinista Defense Ministry defector, described the buildup to reporters last week. Administration officials were jubilant when Defense Minister Humberto Ortega on Saturday confirmed key parts of Miranda's account of the buildup.

Miranda has given about 60 news interviews since Thursday and spoken to dozens of congressmen, including a 1 1/2-hour meeting yesterday with Sen. Christoper J. Dodd (D-Conn.), a leading proponent of the regional peace plan. Miranda is scheduled to meet this morning with Vice President Bush.

One State Department official said yesterday that officials are already looking beyond the lethal aid package to winning new military assistance for the contras next year. "I'm assuming the nonlethal package will go fine," the official said. "The big question is renewed military assistance."

Meanwhile, informed sources said yesterday that the CIA is distributing in Central America a videotape in which Miranda makes allegations about the private lives of top Sandinista officials. Staff writers Helen Dewar and Tom Kenworthy contributed to this report.