White House officials say it is too early to tell what caused the crash of a passenger jet in New York with 255 people on board.

White House Spokesman Ari Fleischer says there were no unusual communications with the plane before it went down. "Were there any conversations between the pilot and any of the towers and communications facilities that would have indicated any trouble the pilots were aware of? The answer to that based on all preliminary reviews is no," said Ari Fleischer.

During a hastily arranged meeting with reporters, Mr. Fleischer said it was far too soon to say what caused the crash. And he urged people not to jump to conclusions. "I just caution everybody that first reports are typically the reports that change the most," he said. "I think you are hearing from people on the ground who are faithfully reporting what they know at this time, what they have seen, what eyewitnesses have reported, and we will continue to update information and provide it as it becomes available."

The White House Spokesman said there were no credible threats of imminent terrorist attacks just before this crash. He said homeland security chief Tom Ridge is monitoring events at the White House, and President George W. Bush is in touch with both the mayor of New York City and the governor of New York State.

Mr. Fleischer was asked if Americans should rethink their plans to fly, given this latest aviation tragedy. He said the President believes they should stick with their travel plans. "We don't yet know what the precise cause of this is," he said. "But prior to September 11, events took place and the public still traveled, accidents took place. And the president continues to believe that people need to travel, the American people need to get on with their lives, and the American people have responded to that."

The White House spokesman said President Bush has offered his condolences to the families of the crash victims. He said the President has also promised further federal aid.