Israeli Prime Minister Ehud Olmert said Sunday that Iran is still trying to build nuclear bombs and the world must make a concerted effort to stop the project.

"Iran has not terminated its pursuit of nuclear weapons," Olmert told a gathering of North American Jewish leaders in Jerusalem. "Iran cannot become nuclear. Israel cannot afford it...the free world must not accept it. We must all do whatever we can to prevent it."

Israel considers Iran a strategic threat because of its nuclear program, its development of long-range missiles and repeated threats to destroy the Jewish state.

Olmert did not give specific warnings about possible Israeli actions against Iran.

Iran denies its nuclear program is aimed at producing weapons.