The U.S. congressional budget agreement has decided to postpone the order of the first Boeing Co. 747 jumbo jet for the new Air Force One fleet to fiscal 2017. The Obama administration had proposed to buy the first Boeing 747 this year and to buy the second one in 2020.

The U.S. congressional negotiators have cut out federal spending bill this week and provide $82.4 million for the presidential aircraft, according to Bloomberg. The amount is $20.2 million less than the U.S. Air Force had sought for fiscal 2016.

The U.S. White House had recommended to postponing the aircraft order, although the Senate had approved full funding for the Air Force One upgrade.

The congressional budget agreement postpones the order of Boeing 747 "until the design for the aircraft's mission systems, which constitute a majority program's projected cost, benefits from further risk-reduction activities, and the Air Force finalizes an acquisition strategy."

The U.S. Air Force was supposed to upgrade the Air Force One fleet starting this year to replace the existing Boeing jumbos flying since the early 1990s.

Boeing 747 is the only U.S. plane that meets Pentagon's requirement of a modified four-engine airliner. The Air Force One costs about $206,000 an hour to fly, according to Daily Mail.

The new Boeing 747 for upgraded Air Force One will be packed with special equipment for presidential flights, including dual auxiliary power units, self-defense systems, military avionics, as well as autonomous enplaning and deplaning systems.

The Air Force One upgrade delay is a setback to Boeing's efforts to gain sales of its 747 models. This year, Boeing has netted only two sales of its 747 jumbo jets, according to Business Insider.

Boeing is having a hard time to find new buyers for the jumbo jets as the cost of purchasing combined with the fact that the planes are relatively energy inefficient makes them impractical.

Boeing 747 was exclusively covering long distance and transoceanic flights for the higher safety it provides.

But as modern turbofan engines became more reliable, and engine failures far less common, the aviation regulations changed resulted in a decrease in jumbo jets demand. Most airlines have turned to twin engine mini jumbo that are more fuel efficient.

In the last eight years, Boeing has sold just 45 jumbo jets. Earlier this year, Boeing announced it will cut the 747 production to just one per month.

With the U.S. White House postponing its 747 order, Boeing is now only relying on Rusia's AirBridge Cargo that said will buy 18 Boeing 747 jumbo jets next year.