Jimmy Carter has found in Argentina the praise and official expressions of gratitude for his activist human rights policy that have often eluded him at home.

Here on a two-day leg of a 10-day swing through Latin America, the former president repeatedly won warm words from Argentina's civilian leadership, which took over from a far-right military junta Dec. 10.

During the 1970s, Argentina was a focal point of Carter's rights policy. It was a time when thousands of people were killed and more than 8,500 others "disappeared" and are believed to have died at the hands of government security forces.

In an editorial today entitled "Thank You, Jimmy," the English-language Buenos Aires Herald said, "It was Jimmy Carter's government that did more than any other group of people anywhere for the cause of human rights in Argentina."

Argentine President Raul Alfonsin and other top officials have praised the Carter policy for saving the lives of hundreds of innocent people caught up in the military counterterror.

During the Carter years U.S. military aid was reduced to a trickle, and U.S. diplomats were instructed to voice rights concerns to their Argentine counterparts in any meeting anywhere in the world. It was an approach that was sharply criticized by then-presidential candidate Ronald Reagan.

"In our debate Reagan said my rights policy was a sign of weakness, that we should support strong governments which are our friends," Carter said in an interview today. "When Reagan took office he immediately sent signals to the generals here that they could expect our renewed cooperation and support."

"If I could make one change, it would have been to strengthen our rights policy, not weaken it," Carter told university students yesterday.

Last night, Alfonsin feted Carter, his wife Rosalynn and an aide to Carter, Robert Pastor, at a private supper at the summer residence.

Today, Carter had lunch at the embassy residence with six human rights activists, including former publisher Jacobo Timerman, Nobel Peace Prize winner Adolfo Perez Esquivel and roving ambassador Hipolito Solari Yrigoyen. Timerman credits the Carter policy with having saved his life; the other two say their release from military-imposed imprisonment was due, in part, to Carter's efforts.

"It was very emotional; there were tears and much embracing and we all wanted to thank him," said Timerman, whose best-selling book, "Prisoner Without Name, Cell Without Number," chronicled his jailing and torture at the hands of the military.

"He kept saying he had risked very little, that there was no reason to thank him," Timerman added. "I told him many ran less risks than he, the head of the most powerful country on earth, but who said nothing."

The luncheon was held at the residence of the U.S. Ambassador, Frank Ortiz, whom Carter fired as envoy to Guatemala in 1980 following a dispute over human rights issues. Ortiz is on a visit to the United States.

Carter arrived in Argentina after visits to Brazil and Peru, two other countries where his government pressed for improvement in human rights and a return to democracy.

In contrast to his reception in Argentina, his three-day visit to Brazil was marked by restrained enthusiasm among politicians and the press and mixed reviews of his administration, which raised tensions between the United States and Brazil.

In Rio de Janeiro, Carter was enthusiastically received by socialist Gov. Leonel Brizola, who credits Carter with having possibly saved his life when he was expelled by Uruguay's military government from his exile there in 1977. But the former president appeared to receive arm's-length treatment from Brazilian President Joao Figueiredo and the two candidates to replace him in next January's indirect elections.

Carter himself admitted in an interview with the news magazine Veja that his strong public pressure on Brazil as president may have unnecessarily exacerbated tensions between the two countries.

"I understand better now that [then president Ernesto] Geisel wanted to take steps . . . on his own without the president of a foreign country pressuring publicly and regularly on this front of civil liberties and human rights," the magazine quoted him as saying. "It is understandable that he [Geisel] became a little irritated."