The officials have knowledge of the investigation and tell The Associated Press the attack was to take place in Canada. They aren’t authorized to discuss the investigation and would speak only on the condition of anonymity.
Amtrak and Via Rail Canada jointly operate routes between the United States and Canada, including the Maple Leaf from New York City to Toronto.
Two men were in court in Canada on Tuesday, accused of plotting with al-Qaida members in Iran to derail a train.
Canadian authorities have charged them with conspiring to carry out an attack and murder people in association with a terrorist group.
Police say the men never got close to carrying out the attack.