Rebel leader Jonas Savimbi said yesterday he believes a cease-fire can be achieved in Angola by the end of the year because of new involvement by the superpowers -- particularly the Soviet Union -- in peace negotiations.

Savimbi, who is in Washington to meet with President Bush and other officials, also said his National Union for the Total Independence of Angola (UNITA) no longer insists that the Angolan government recognize UNITA as a political party before cease-fire negotiations may begin.

Savimbi, whose group has received millions of dollars in U.S. aid, said he believes UNITA and the Angolan government can simultaneously work out details of a cease-fire and an agreement on "political principles" for free elections.

Soviet officials conferred with UNITA representatives in Lisbon last week -- a meeting described by Savimbi as the first between the Soviets and the rebel group. The Lisbon talks, which ended Thursday, are to resume later this month.

A member of Savimbi's entourage who took part in the Lisbon meeting said he was told by Soviet officials that they are seeking ideas both from the rebels and from the Angolan government in "looking for a solution" to the 15-year civil war.

Savimbi said Secretary of State James A. Baker III and Soviet Foreign Minister Eduard Shevardnadze also had discussed the Angolan situation during a meeting in New York last week. Savimbi is scheduled to meet with Bush Tuesday.

Savimbi said he believes that UNITA's willingness to drop its demand for political recognition as a condition for cease-fire negotiations had led to progress in both cease-fire and political talks. "We are satisfied with this round of talks," Savimbi said.

The rebel leader expressed hope both for a cease-fire by the end of this year and for free elections in Angola by the end of 1991 under timetables being discussed in the negotiations. The Angolan government has been "sending different signals. It seems to me it wants to cooperate," Savimbi said.

The Angolan government has said it cannot recognize UNITA until it changes its constitution to allow a multi-party system, but the government has insisted that process is underway. The current constitution recognizes only a one-party government.

In the meantime, Savimbi said, UNITA has agreed to restrict its military positions once a cease-fire is reached. "We have agreed to set some zones where the guerrilla army will be," Savimbi said. He insisted, however, that a cease-fire would not require disarmament.

Savimbi said he came to the United States to bring Bush up to date on progress in the negotiations, but his visit also takes place as Congress prepares to vote on continued covert aid to UNITA. The administration is seeking about $50 million in aid in the intelligence appropriation.

Several members of Congress have proposed to eliminate aid to UNITA, place a six-month moratorium on such aid or remove it from the covert intelligence budget and designate it as an overt aid program that can be voted on separately.

Although he insisted he is not here to become involved in the congressional funding debate, Savimbi echoed the White House position, saying the aid is needed to keep negotiating pressure on the Angolan government. "If the aid to UNITA is put in doubt, then this is going to hamper the negotiating process," Savimbi said.

He also urged Congress to stop debating whether UNITA aid should be covert or overt, contending that such debate may weaken UNITA's negotiating position.