Kirchner (l) joined those remembering the victims
The Argentine president stood alongside Jewish leaders to mark the ninth anniversary of a community centre bombing that killed 85 people and injured more than 200.
After the ceremony, Nestor Kirchner called the unresolved investigation of the 1994 bombing of the Jewish centre a "national disgrace".
The country's 300,000-strong Jewish community has long criticised the Argentine authorities for failing to apprehend those responsible.
But they have welcomed signs of a deeper commitment by President Kirchner, who ordered a new inquiry soon after taking office.
Eighty-nine people died when a van stocked with explosives drove into the Israeli-Argentine Mutual Association (Amia) centre in July 1994.
The centre has since been rebuilt.
The Lebanese militant group Hezbollah was initially accused of a role in the blast - as was Iran, which strenuously denied any involvement.
Over the past nine years, the case has been plagued by disappearing witnesses and unexplained delays.
On Friday, thousands of people gathered in the downtown street in Buenos Aires where the seven-storey building was levelled.
A siren wailed at the exact moment of the blast and candles were lit as the names of the victims were read aloud.
"We have suffered nine years of frustration and injustice," said Abraham Kaul, President of Amia.
Some in the crowd told Associated Press they hoped Kirchner would finally help bring some closure.
"I want justice," said 54-year-old Paulina Lanando. "We'll give Kirchner one year to get to the bottom of this. But we want answers, and we want them now."
The bomb completely destroyed the centre
Soon after taking office in May, President Kirchner gave permission for sealed intelligence service files on the attack to be opened.
His decision effectively annulled a decree by his predecessor, Eduardo Duhalde, that sealed the files and prevented agents from the State Intelligence Secretariat (Side) from testifying.
Fourteen such agents are expected to do so now, including Hugo Anzorreguy, Side's head at the time of the bombing.
Mr Kirchner's office said at the time the decision would "lift the veil of state secrecy" surrounding Side.
Correspondents say the documents might also provide clues to whether alleged blunders by the security forces before the attack were covered up by the authorities.