“We have not forgotten, and we never will,” said Pompeo, who was joined by Latin American government ministers in Buenos Aires for counterterrorism talks.

Washington offered US$7 million to find alleged perpetrator Salman Raouf Salman and imposed sanctions on him, in tandem with Argentina’s announcement that it was designating Hezbollah as a terrorist group.

Ariel Eichbaum, president of the Jewish centre known by its Spanish acronym AMIA, said responsibility for the attack lay with Hezbollah and Iran, the primary sponsor of the Lebanese Shiite Muslim militant movement.

Eichbaum asked all countries to “help us find those responsible and bring them to justice.”

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After 25 years, no one has been brought to trial and the case has been bogged down in Argentina amid allegations of political interference and high-level corruption.

Iran and Hezbollah both deny responsibility for the attack, and persistent sceptics have questioned the motivation. Hezbollah was also accused of carrying out a deadly attack two years earlier against the Israeli embassy.

The US is encouraging Latin American countries to follow its lead in aggressively designating groups or individuals as terrorists, as demonstrated by Argentina’s action.

“In the face of a global threat like Hezbollah, it is every sovereign nation’s obligation and responsibility to comply with sanctions designed to keep all of us safe,” Pompeo said as he opened the talks with fellow ministers.

“Solidarity is the antidote to the terror threat,” he said.

Argentina’s Foreign Minister Jorge Faurie said that the Hezbollah designation would allow the country to freeze the group’s assets and ban the entry of its members.

Pompeo said he expected “many” Latin American countries to follow Argentina’s lead on Hezbollah, although none immediately announced they would do so.

The US Treasury Department said Salman, also known as Salman al-Reda, masterminded the 1994 attack and “has directed terrorist operations in the Western Hemisphere for Hezbollah ever since”.

Salman reportedly has joint Lebanese and Colombian citizenship, allowing him to move more easily across Latin America.

The Treasury Department said Salman also served as a handler for a man arrested by Peru in 2014 for allegedly planning to attack Israelis and Jews.

Asked where Salman is believed to be now, a senior US official said: “We think he is probably somewhere in the Middle East.”

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The actions come amid high tensions between the United States and Iran after President Donald Trump left a denuclearisation accord and slapped sweeping sanctions on Tehran.

Pompeo on a visit in March to Beirut vowed to stop “all malign behaviour” by Iran including activities by Hezbollah.

But Lebanese officials defended the group, which has emerged as a major political party with cabinet ministers and which won popular support through its guerilla campaign against the Israeli occupation of southern Lebanon.

More than 20 countries took part in the counterterrorism talks in Buenos Aires. They will next meet in Colombia in January on the anniversary of an attack by the ELN guerillas on a police academy in which 22 people were killed.

Pompeo is also meeting with Argentine President Mauricio Macri in a show of support for the centre-right leader, who is down in the polls ahead of October elections after pushing through unpopular austerity measures as part of an IMF bailout.