OTTAWA — Canada won't ignore threats from Iran and the Hamas-led Palestinian government against Israel, warns Prime Minister Stephen Harper.

Harper made the pledge Tuesday as he spoke at a Parliament Hill ceremony in remembrance of victims of the Holocaust.

The prime minister said the world should never again stand by and ignore signs of trouble when they appear.

"We will not ignore them when they are done by Hamas. We will not ignore them when they are from the government of Iran," Harper told several hundred people beneath the Peace Tower.

Iranian President Mahmoud Ahmadinejad has made repeated threats against Israel. As recently as Monday, he said Israel was a "fake regime" that "cannot logically continue to live."

Hamas, which defeated the more moderate Fatah party in January's Palestinian elections, continues to support violence against Israel.

Hamas has also outright rejected the presence of a Jewish state in the Middle East, and -- despite an international outcry -- has refused to accept interim Palestinian-Israeli peace accords.

Harper says ignoring such threats could place the world on a path to repeat atrocities such as the Holocaust.

"We have learned the lessons of the past,'' Harper said. "We will learn them, or we will be doomed to repeat them."