The U.S. government has outlined an ambitious program of human-rights improvements and other changes in El Salvador to aid the Reagan administration in defending before Congress the continuation of economic and military aid here, according to a State Department cable to the embassy.

The recommended actions include major restructuring of the Salvadoran armed forces to clamp down on human-rights abuses, a new public posture on "dialogue"--a code word here referring to possible negotiations with leftist guerrillas--and meeting agrarian reform goals for land distribution and payment to former owners.

Francisco Jose Guerrero, a Salvadoran Cabinet officer who serves as chief of staff to the president, said that while his government agreed with the goals expressed in the cable there were no new programs or structural changes under way of the kind recommended by the State Department.

He rejected the idea of restructuring the armed forces as "very strange" in the middle of a war.

Guerrero said the government would make "something" public before the administration's aid-certification deadline, but said that the announcements would concern current government activities and goals that coincide with the certification in Washington rather than new programs.

The program outlined by the cable touches on all the points about which President Reagan is required by Congress this month to certify Salvadoran government progress as a condition for continued U.S. economic and military aid. The points are human rights, agrarian reform, control of the armed forces and efforts toward democracy and a political solution to the war.

Embassy officials here said the cable was authentic and described it as one that best expressed U.S. policy in El Salvador. One of the officials, however, called the recommendations a "wish list."

The cable, signed by former secretary of state Alexander M. Haig Jr., was obtained from the Boston-based Central American Information Office, a private research group that publishes background material about the region. Group member Eric Shultz said the cable was obtained by "one of the members" from an undisclosed source, and distributed to "a few reporters and newspapers" in the United States and Mexico.

The cable instructs U.S. Embassy officials to "urge early [Salvadoran government] acceptance of a human-rights program at least as ambitious as these steps to allow us to meet requirements of the July congressional certification."

The cable also says that "careful monitoring" by the embassy "will ensure that impetus for improvements is maintained . . . ."

Potentially the most controversial recommendation in the cable is that calling for structural changes in El Salvador's "security forces," which are a combination of regular Army, semi-independent police and National Guard forces, along with paramilitary units. The cable lists as an "initial step that might be implemented now" the transfer of "intelligence and other military duties" from the National Guard and Treasury Police to the Army and the creation of a single national intelligence service controlled by the Army.

The National Guard and Treasury Police and paramilitary units working with them have a reputation for abuses against civilians that is far worse than that of the Army, which is considered to be more responsive to U.S. human-rights concerns.

The cable also calls for "eventual integration of all military-related functions into the Army and . . . formation of a civilian police force."

Restructuring of the armed forces to weaken the security forces, moreover, would appear to meet a major demand of the leftist coalition known as the Democratic Revolutionary Front--Farabundo Marti National Liberation Front.

An embassy official said in an interview that the Salvadoran government "is looking seriously at their [military] structures, and we expect some progress" in that point of the cable's recommendations after a current surge in fighting has died down. Guerrero denied that any changes were contemplated along those lines.

Guerrero and embassy officials agreed, however, that several of the recommendations coincided with measures mentioned in speeches by President Alvaro Magana, including setting up a commission of "notables" to make recommendations to the government on a program of "pacification" and initiatives for improving the now barely functioning civilian judicial system.

In a section apparently aimed at congressional concern for progress toward a political solution to the war, the cable urges that "the government seize the initiative from the [leftist coalition] by offering opportunities for elements of the extreme left to return to the political mainstream and by occupying the high ground in contesting international opinion on the issue of dialogue with the left."

Guerrero said there is "no dialogue in progress" with the left and said the possibility of negotiations was "closed by the elections of March 28" in which rightist parties won a majority in the new assembly.

The State Department message also urges that the Salvadoran government "remain committed" to agrarian-reform goals calling for the processing of 50,000 new applications by peasants for titles to land, and conferring of 12,000 deeds for small farms.

[Meanwhile, a U.S. Embassy spokesman said that the United States does not plan to act on recommendations from a high-ranking Western military official that more U.S. military advisers be sent to El Salvador, United Press International reported.]