Angola has offered to remove all 40,000 Cuban troops from its soil as part of an overall southern Africa peace settlement, according to Manuel Pacavira, Angola's new ambassador to the United Nations.

"We stated our willingness, our agreement in principle, to the withdrawal of Cuban troops from our territory on a shortened timetable," Pacavira said in an interview here Thursday, confirming the State Department's recent statement that Angola had taken "an important step" at the latest round of U.S.- Angolan negotiations held in Luanda late last month.

The State Department regards the Angolan shift on the crucial Cuban troop withdrawal issue as a potential breakthrough in the long-deadlocked negotiations conducted with Angola and South Africa by Chester Crocker, assistant secretary of state for African affairs.

The United States and South Africa insist, for different reasons, on the withdrawal of all Cuban troops. South Africa has refused to allow U.N.-supervised elections in neighboring South African-administered Namibia, or to withdraw its own troops from there, unless all Cuban troops leave Angola.

The United States has insisted upon a total Cuban withdrawal before it will press South Africa to accept U.N. elections in Namibia or establish diplomatic relations with the Marxist government of Angola.

Pacavira said that Angola's offer must be part of "a package deal" including independence for Namibia and an end to U.S. and South African aid to opposition forces led by Jonas Savimbi's National Union for the Total Independence of Angola (UNITA).

"The fundamental question for the United States is the withdrawal of Cuban troops and a reduction in the timetable," he said. "We agreed with that, and we want to contribute {to a solution}. But we have another fundamental question which is the security of our country."

"This security can only be assured with the independence of Namibia, the withdrawal of South African troops from our territory, stopping aggression against our territory and stopping aid to UNITA provided by the United States and South Africa."

Pacavira said Angola regards the current talks with the United States as a "global negotiation . . . a package" in which Angola will obtain "international assurances" that South Africa will stop its incursions into southern Angola and its aid to UNITA in return for a total Cuban troop withdrawal.

The United States has resisted including the issue of U.S. aid for UNITA in the talks but is now considering some form of "international assurances" for Angola's security in connection with U.N.-sponsored elections in Namibia that apparently would include an aid cutoff.

Pacavira's confirmation of an Angolan offer for a total Cuban troop withdrawal came after a conflicting statement from another Angolan ambassador, Luis de Almeida.

Almeida, Angola's ambassador to France, said at a Feb. 5 news conference that Angola had "always" accepted negotiating "the issue of withdrawing the Cuban troops."

However, U.S. officials said Angola previously had only offered to withdraw Cuban troops from the southern portion of the country and send home two-thirds of the troops while reserving the right to decide unilaterally when the remaining Cuban troops would leave.

One U.S. official said the two sides are now talking about two timetables, one for the withdrawal of Cuban troops stationed in southern Angola and another for Cuban forces left temporarily in the north.

State Department officials say Angola next must provide a short timetable for a total Cuban troop pullout, which the United States can present to South Africa for its approval to proceed with U.N.- supervised elections for independence in Namibia.

Pacavira said he had no information whether this step might be taken.

He also expressed skepticism that South Africa would leave Namibia even after the Angolan offer unless the United States uses its influence with Western Europe, South Africa's major trading partner, to get them to pressure Pretoria as well.