KIBBUTZ MAAYAN BARUCH, Israel (AP) _ Dennis Goldberg, a freed South African political prisoner, said Sunday he was thrilled to be out of jail after 21 years, but that it was hard to leave behind his comrades fighting white supremacist rule.

''It was traumatic,'' he told The Associated Press in an interview at this northern Israeli kibbutz, or collective farm, where his daughter lives. But he said his years in prison had become so difficult ''I couldn't carry it on.''

Goldberg, 55, South Africa's longest-serving white political prisoner, was freed last Thursday in exchange for signing a renunciation of violence as a means of fighting South African rule.

He said he expected his action would cause some anger among his former colleagues, ''but I did what I had to do. If I was a bad soldier, I'm sorry.''

Goldberg, allegedly a member of the now-banned Communist Party of South Africa, was arrested in 1962 and jailed for life in 1964 along with Nelson Mandela and other black leaders. They were accused of planning violence to overthrow white rule.

Mandela refused earlier this year to renounce violence in return for freedom, but Goldberg accepted.

Goldberg said he thought Mandela ''was right'' but added, ''for me, I couldn't carry it on (in prison) at that stage ... This happened to come at a time when my own psychological need to get out was at its strongest.''

''For some time now - six months - I've been feeling ... 'It's time to go. You've had enough,''' said Goldberg. ''There's always been a conflict between what I know to be my duties to the movement and my personal needs at a particular time.''

Goldberg, dressed in a maroon jacket and beige trousers he bought when he was released Thursday, said he hopes to return to South Africa some day ''if I can be effective there.''

He said leaving South Africa ''was not a condition (to his release,) but security police would not leave me until I was on the plane.''

Goldberg said his ability to make bombs led to his capture and arrest in Johannesburg. Knowing that the government was clamping down on dissidents, he intended to leave South Africa but his comrades asked him to stay and make bombs, he said. Before he could begin that work, he said, he was arrested.

Goldberg said he intends to leave Israel for London after visiting his daughter Hilary, 30, at this kibbutz of'sbout 300 people about three miles from the border. His wife and son David, 28, live in London.

''Whether I'm going to earn my living as an engineer and practice politics part time or make a living part time and practice politics full time, I can't tell you now,'' he said.

''There are so many choices,'' he said. ''I'm still flying. I'm high on just being free.''

Goldberg had harsh words for what he termed the failure of the U.S. and Israeli governments to protest more strongly against South Africa's apartheid policies.

''I think that the support of the state of Israel for the South African government ... is one of the most horrifying things I have experienced,'' he said.

''To be confronted by prison officials who say: 'You're a Jew. Israel does what we do,' was one of the nastiest experiences,'' he added.

Of the United States, he said: ''It is clearly apparent that the United States government, while talking change, at the same time protects South Africa on every possible occasion. In the name of maintaining order and orderly change, they will slow it down to a dead stop.''