According to Gerstenmaier, it is simply not possible for NASA to announce a date by which it would be able to send a manned mission to Mars as the agency doesn't have enough money to accomplish the mission.
Because of this expense, NASA has had to postpone designing the vehicles that would land on Mars.
NASA has been preparing for a manned mission to planet Mars but the prospect of landing humans on the Red Planet faces financial hurdles.
Gerstenmaier comments come almost a month after Lt. Gen. Larry James, the deputy director of NASA's Jet Propulsion Laboratory, said the space agency had its sights set on Mars for the near future.More news: Terbium Metal Powder Market - Global Industry Size, Growth, Trends and Forecast 2017
In his address, Gerstenmaier explained that going by NASA's budget allocated to it by the USA government, it is simply unfeasible to launch a crew to the Red Planet.
Fortunately, NASA isn't our only hope when it comes to a manned Mars mission - one of their contractors, SpaceX, is planning one.
For the most part, it would seem that some of the biggest obstacles that prevent the U.S. space agency from achieving such a goal are the costs that its current rocket technology would incur. Gerstenmaier hinted at more in depth moon exploration instead of their most current lunar plans to build Deep Space Gateway in the Moon's orbit.
Mr Gerstenmaier's admission comes just days after Vice President Mike Pence said that the USA will "usher in a new era" of American space leadership, but budget cuts for Nasa from the Trump Administration seem to have taken its toll. Despite all those announcements, it appears there are many glitches for NASA along the road to Mars. Earlier this year, Pascal Lee, of Mars Institute, a non-governmental organization whose goal is to advance the scientific study and exploration of Mars, estimated that the mission could cost up to $1 trillion over a course of 25 years.