El Salvador rejects offers to hold peace talks with rebels

El Salvador's government will not begin talks with rebel insurgents in the near future, despite rebel overtures and mediation efforts by the Costa Rican government, high-ranking Salvadorean officials say.

Their remarks seem to reflect a stand that has hardened somewhat since June, when key officials of the newly elected government suggested that at least some rebels might be brought back into the mainstream political process within six months to one year.

Salvadorean officials here say that before talks with rebels are held, the 21 /2-month-old government must consolidate its political power and ''create the necessary conditions'' for mediation.

''It is not wise to act until we are sure that what we are doing is good for the country, and not for the insurgents,'' says Julio Adolfo Rey Prendes, minister of the presidency.

Salvadorean officials feel that if they can consolidate their civilian government, the rebels will eventually be weakened.

''If we can restore legitimacy to the government,'' says one official, ''we can score a political victory which will mark the end of the rebel movement.''

In May, just after Jose Napoleon Duarte was elected president of El Salvador, Costa Rican officials offered to help arrange an ''open dialogue without preconditions'' between the rebels and the government. The Costa Ricans offered their own country, or the Costa Rican Embassy in San Salvador, as a site for the talks.

About the same time, the rebels affirmed their interest in a dialogue in a letter to President Duarte sent through the Roman Catholic Archbishop of San Salvador, Arturo Rivera y Damas.

The Duarte government, however, refuses to respond to either the Costa Rican efforts or the rebel offer.

Government officials say the rebel letter does not constitute a ''formal proposal'' and will therefore go unanswered. They also discount Costa Rica's overtures as informal.

Costa Rican President Luis Alberto Monge has personally offered to act as an intermediary and is ready to make ''a major effort to promote dialogue.''

But Mr. Prendes says, ''The declarations by Monge ... are not a real proposal by the Costa Rican government to Duarte. They haven't talked to us officially.''

President Duarte has repeatedly stated in recent weeks ''that he will not talk with armed factions,'' a reference to the guerrilla forces making up the Farabundo Marti National Liberation Front. The political wing of the guerrillas, the Democratic Revolutionary Front (FDR) did not engage in the fighting.

The strategy of the Duarte administration appears to be aimed at splintering the FDR leadership and evenually reincorporating some its leaders into the nation's mainstream political activity.

Duarte aides privately discount any possibility that dissidents led by the FDR's Guillermo Ungo, who in 1972 was Duarte's vice-presidential running mate, can be reincorporated into the political landscape.

These officials target the 1988 elections as the first realistic opportunity for Mr. Ungo and other rebel political leaders to take part in the electoral process.

Duarte's strategy is two-tiered. His supporters are trying to undercut Ungo's international base of support as they try to entice him into the political mainstream.

Dr. Rene Fortin Magana, a confidant of the new President, has petitioned a new international social democratic organization to withdraw support for Ungo and instead back Magana's fledgling Democratic Action Party as the legitimate representative of the social democratic movement in El Salvador. The move, according to Duarte stalwarts, would seriously undercut the prestige of Ungo and the FDR.

The government's refusal to open talks with the rebel front or to allow the FDR to speak for the insurgents probably means a continuation and possible escalation of the civil war, most observers here say.

''There are certain groups,'' Prendes says cryptically, ''that will never accept peace, that will keep on fighting.''