President Jose Napoleon Durate's government is interested in receiving more U.S. helicopters and troop transports, along with radar and communications equipment to strengthen a "quick-reactio force" to wipe out guerrilla strongholds.

Duarte said that outside aid to guerrilla forces in El Salvador has increased in both size and sophistication. "They are better armed now," Duarte said, although he did not provide details as to types of weapons, origin or the source of governnment information, "and they have much more radio and communications equipment."

Duarte declined to comment in an interview Monday on whether the new equipment had already been requested, whether it was to come out of the current $35.4 million of authorized U.S military assistance or a requested $26 million for fiscal 1982, or if it would require additional funding.

[In Washington, a State Department official said that discussions with the Salvadoran government in military equipment were "a continuing, ongoing thing, without a beginning or end. Our military group sits down with them virtually every day" to discuss current needs, the official said, without particular reference to what fiscal year or program the money would come out of.]

["They kind of rely on us to say whether we can or cannot finance" the "things they would like to have." The administration is expected to amplify its policy on El Salvador in a speech today by Assistant Secretary of State THOMAS O. Enders.]

In a wide-ranging session at his Presidential Palace office, Duarte also charged former U.S. ambassador to El Salavador Robert E. White and San Salvador Archbishop Arturo Rivera y Damas with obstructing his government's investigation into the December deaths of four American missionary women.

Duarte said White and the archbishop had jumped to conclusions about who was responsible for the crime and "began to give declarations that did not correspond to reality. They blamed one sector [of the security forces] and it turned out to be another sector that was responsible for the crime."

Immediately after the women's bodies were found Dec. 3, White said that he had information that the National Guard, one of three Army-headed police organizations collectively known as the Salvadoran security forces, had information reguarding the crime. Subsequently, he directly accused the security forces.

On Dec. 8, Rivera y Damas charged that the killins were "the culmination of four years of persecution of the church" and had increased with the current government, for which "the security forces and ultrarightist gangs" were to blame.

Six National Guard soldiers were arrested in connection with the killings following ballistics tests by the FBI that the Salvadoran government said implicated them. Duarte said they would be "taken before a judge as soon as the current stage of the investigation is finished," but declined to speculate on the time frame involved.

The bullets for the tests reportedly were not discovered at the crime scene until some time later. With obvious pride, Duarte explained how he had designed a grid with which to locate them.

"From eyewitness reports," he said, "I drew a radius in which the bullets could be found. We followed the map to see what roads could have been used, and we dug in those spots. From the autopsy ballistics report, I found how deeply the bullets could have been buried.

"Since the nuns were executed when they were lying on the ground, the bullets were not very deep into the ground. I ordered some people to go dig for the bullets, and they were found."

Earlier accounts of the killings have said that glass fragments were found in the head of at least one of the victims and, in testimony last March, Secretary of State Alexander M. Haig Jr. said that the women may have been "attempting to run a [government] roadblock, which was followed by "an exchange of fire" that killed them.

Duarte also disputed church leaders, including Rivera y Damas, who have charged security force responsibility in the apparent mass killing last week of 28 persons whose bodies were found under a bridge in the northern province of Chalatenango, an area of strong guerrilla activity.

Duarte accused the guerrillas of the killings and said the victims, who were buried before being officially identified, and whose bodies have not yet been exhumed, were members of civil defence patrols organized by the Army.

"The fact that they had their thumbs tied behind their backs," he said in reference to common practice of government troops and police with prisoners, "or that the murderers drove to the scene of the crime in trucks after the curfew hour does not indict the security forces.

"The guerrillas have figured out that if they tie their victims' thumbs, everyone will jump to the conclusion that it was the work of the security forces. As for the curfew hour," Duarte said of charges that the security forces use the curfew hours to kill suspected civilian subversives, "I would say that this is when the left can operate most freely. We use the curfew hour to give our troops a chance to rest."

Duarte broadened his list of enemies to his government to include "the ideological left" and private sector organizations opposed to government reforms. He contended that the leftist guerrillas are losing strength.