A co-director of the Indochina Resource Center in Berkeley, Calif., said yesterday that the current fighting in South Vietnam is not a prelude to another major offensive but is instead an attempt by the North Vietnamese to force the United States to adhere to the Paris Peace Agreement.

David Marr, who returned from a trip to North Vietnam in mid-January, explained his analysis in an interview after addressing a group of 25 at the East Asian Research Center on the North Vietnamese economy and culture.

Marr said that gains by Saigon forces and continued U.S. support have convinced leaders of the Provisional Revolutionary Government of South Vietnam (PRG) and North Vietnam that the United States is not going to follow the Paris agreement and end military and political involvement in South Vietnam without pressure.

More Fighting

"My impression," Marr said, "is that military action against Saigon will increase in 1975," but he added that both the PRG and North Vietnam only want to defeat the Saigon forces to "demoralize them so they disband and return home."

The North Vietnamese will not go any further and launch a major offensive, Marr explained, because "North Vietnam does not want to give the United States any pretext to resume bombing."