A large U.S. spy satellite has lost power and propulsion and could hit the Earth in late February or early March, government officials said Saturday.

The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said.

The officials spoke on condition of anonymity because the information is classified as secret.

“Appropriate government agencies are monitoring the situation,” said Gordon Johndroe, a spokesman for the National Security Council. “Numerous satellites over the years have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate any possible damage this satellite may cause.”