The pact, signed in January 2013 by Argentina’s former foreign minister, Héctor Timerman, and his Iranian counterpart, Ali Akbar Salehi, proposed the creation of a joint commission to help solve the 1994 bombing, which killed 85 people.

Argentine prosecutors have accused Iran of being behind the attack, a charge that Iran has denied.

Alberto Nisman, the Argentine prosecutor who led the investigation, died this year of a gunshot wound to the head in mysterious circumstances. Mr. Nisman had claimed that the pact was part of an effort to disguise a secret deal arranged by Mrs. Kirchner in which Argentina would receive trade rewards from Iran in exchange for shielding Iranian officials from charges that they had orchestrated the bombing in 1994. Mr. Nisman’s accusations died in Argentina’s courts.

Jewish leaders, some victims’ families and the political opposition to Mrs. Kirchner criticized a provision of the pact that called for Argentine investigators to interrogate the Iranians in Tehran, saying it could pave the way for impunity for the suspects. Mrs. Kirchner’s administration said it was the only way of moving forward with the unresolved case.

The pact was approved by lawmakers, but it was declared unconstitutional by judges in a ruling last year because it was considered an overreach by the executive branch. Mrs. Kirchner’s government had appealed the decision to a higher court. In a turn that highlighted the acute politicization of Argentina’s judiciary, two of that court’s judges were then recused in moves backed by Mrs. Kirchner’s supporters, and controversy surrounded the process to replace them.

“There were a series of judicial controversies that turned it into a scandal,” Mr. Garavano said, referring to the recusals. He said those controversies had influenced the decision to cease the appeal, adding that it was a political move ordered by Mr. Macri.