The leadership of El Salvador's leftist opposition has denied U.S. charges that it is receiving weapons from countries in the Sovet Bloc.

A statement by the political-military commission of the two federations representing the leftist guerrilla groups and their civilian allies "emphatically denies" that the guerrillas have "received arms from the governments of Vietnam, Ethiopia, Cuba, Russia or any other government."

Sources close to the two federations in Washington and Mexico City confirmed that the statement, widely distributed here last week, is authentic. The federation of guerrilla organiztions is called the Farabundo Marti National Liberation Front and the organization of cilvilian groups -- including political, student, labor and peasant -- is called the Democratic Revolutionary Front.

The statement said the guerrilla organizations obtained their weapons in several ways, including capturing them in combat and buying them on the international market with the "solidarity of peoples and organizations through the world."

The West German media reported recently that leftist organizations there had raised $500,000 to buy weapons for the Salvadoran insurgents.

The statement said "many" of the weapons "have been manufactured by our own combatants."

The only "incontrovertible truth before the international conscience is the growing provision of arms and military training" by the United States to the government of El Salvador, the statement said.

The statement said the U.S. diplomatic drive using documents purporting to prove foreign communist military aid to the rebels is "a genuine insult to the intelligence and dignity" of the countries to which it is directed.

The statement said the opposition federations are "open to political solutions which do not betray the interest of our people." It did not elaborate or discuss why they have declined offers for talks with the Salvadoran government.

Meanwhile, Nicaraguan Foreign Minister Miguel d'Escoto also denied U.S. charges that his country is sending arms to Salvadoran leftists.