A top Israeli official vowed Friday to "prevent Iran from acting" if it seeks to use a nuclear weapon, amid growing impatience over Tehran's refusal to come clean on its nuclear program.

Israeli Deputy Foreign Minister Danny Ayalon warned on a visit to Argentina that a nuclear-armed Iran would have "ramifications throughout the world" and allow Tehran to "achieve hegemony in the Middle East.

"In the worst case scenario, Iran could use a nuclear weapon," he said in Buenos Aires.

"We will protect our citizens, our interests everywhere in the world and prevent Iran from acting."

Daniel Carmon, deputy director general of the Israeli Foreign Ministry, called Iran "a threat to the entire world," stressing that "this threat requires an immediate response."

They spoke during a ceremony marking the 20th anniversary of an attack on the Israeli embassy in Buenos Aires.

Israel, like the United States, has refused to rule out military action against Tehran, fearing that its uranium enrichment program masks a drive to build a nuclear bomb. Iran denies the charges, insisting its program is aimed at producing energy and other peaceful purposes.

But Washington, which has no diplomatic relations with the Islamic Republic, has stressed there is still time to resolve the standoff. Israel considers Iran a threat to its very existence.

Carmon was consul in Buenos Aires when the Israeli Embassy was destroyed on March 17, 1992 in a car bomb attack that left 22 people dead and 200 wounded.

"Iran was directly responsible for what happened here," he said.

Two years later, a bombing leveled a Jewish charity building in Buenos Aires, killing 85 people. Israel also accuses Iran of being responsible for that attack.

The blast that destroyed the seven-story AMIA building, also injuring 300 people, was the most serious attack against Argentina's Jewish community, the biggest in Latin America with an estimated 300,000 members.

On Wednesday, US President Barack Obama warned Iran that the window for diplomacy to solve a nuclear showdown was "shrinking," stiffening his rhetoric ahead of looming new talks on the issue.