The first veteran of the North Vietnamese Army to make an official tour to the United States says the time has long passed when the United States and Vietnam should be trading goods and sharing knowledge.

Nguyen Ngoc Hung, 42, was in San Francisco earlier this week to talk with veterans of Swords to Plowshares, which - in concert with the Vietnamese-American Friendship Association - sponsored his visit to San Francisco.Hung, a veteran of the NVA's 320th Division, has been to New York, Washington and Wisconsin to ask American veterans to help Vietnamese work toward a normalization of relations between their governments.

The United States has had an embargo on trade with Vietnam since the end of the war in 1975, Hung pointed out. "Here in the States, the government told everybody to forget about the war, but in reality the government has not forgotten about the war. It is using a very vengeful hand in dealing with Vietnam."

By contrast, he has been met with warmness by American vets, said Hung. "None of them has shown hostility, but shook hands with me and said, `Welcome to the United States.' One I met in New York City thought I was on a propaganda tour, but in the end he, too, shook hands and welcomed me."

There is a shared experience between veterans of both countries, said Hung. "After the war, our government believed our soldiers didn't have psychological problems, but we did have problems - nightmares, flashbacks. I don't think it makes a difference, winning or losing the war. I think it is a human thing. To see so many killings, to see men torn apart by grenades, by shelling - these experiences will not go away."

Hung, who fought with the NVA from 1969 to 1975 in the Quang Tri area, said, "American firepower was certainly something. Most of our casualties came from the B-52, from helicopter gunships, by artillery. . . . The most frustrating was the B-52 because you didn't know when they would come, night or day, and there was no way to fight against them."

Hung's six years in the Vietnamese army started in 1969, after massive casualties in the Tet offensive caused the government to start drafting students. One of the first students to be drafted, Hung survived to attend Hanoi's Foreign Languages College, majoring in English after the war.

"It was because of a promise I made to a dead friend," he said. "We were talking about what we would do after the war and he told me he wanted to become a teacher, and I said I wanted to be one, too. That afternoon he was killed, and I took it as a promise to him that I would return to college and become a teacher."

Hung, a lance corporal with the 320th, said he has talked with men from his own unit often since the war. "I live in Hanoi and they always come to see me when they are in the city. We spent all those years together in the jungle, shared so many things together . . . but when they come to see me, for some reason, we never talk about the war."

Hung has visited the Vietnam memorial in New York, where he burned incense for the dead, and the memorial in Washington, D.C.

"It was an eerie feeling," he said. "The names starting with one line, then more and more. . . . I talked to a veteran looking at the name of his friend and asked if he is ever able to forget, and he said that he remembers his friend every day and thinks, `Why him and not me?' "

He knows what that veteran was talking about, said Hung, and it is that bond of memory he sees as bringing America and Vietnam closer together. "I don't think government-to-government talks are going to do it. I think it must be people-to-people, veteran-to-veteran."