US aerospace major SpaceX has announced plans to fly two private citizens on a week-long trip around the moon next year.

The two individuals approached SpaceX for the trip and they have "already paid a significant deposit" to do a moon mission, the company said in a statement on Monday.

"Fly me to the moon ... Ok," SpaceX CEO Elon Musk tweeted after the announcement was made.

Lift-off will be from the Kennedy Space Center's historic Launch Complex 39A at Cape Canaveral in Florida -- the same launch pad used by the Apollo programme for its lunar missions.

"Like the Apollo astronauts before them, these individuals will travel into space carrying the hopes and dreams of all humankind," SpaceX said.

Following the announcement about the private space mission around the moon, NASA said it "commends its industry partners for reaching higher".

"For more than a decade, NASA has invested in private industry to develop capabilities for the American people and seed commercial innovation to advance humanity's future in space," the US space agency said in a statement on Tuesday.
 

The two tourists would be sent on a SpaceX's Dragon 2 capsule, launched on the company's Falcon Heavy rocket.

"NASA's Commercial Crew Program, which provided most of the funding for Dragon 2 development, is a key enabler for this mission," SpaceX said while thanking the US space agency "without whom this would not be possible".

"Falcon Heavy is due to launch its first test flight this summer and, once successful, will be the most powerful vehicle to reach orbit after the Saturn V moon rocket," the company said.

SpaceX said the space shuttle Dragon was designed from the beginning to carry humans and already has "a long flight heritage".

For the Hawthorne, California-headquartered company, the private trip around the moon is one step on the way to their goal of transporting humans to Mars.

Later this year, as part of NASA's Commercial Crew Program, SpaceX will launch its Crew Dragon (Dragon Version 2) spacecraft to the International Space Station (ISS).

This first demonstration mission will be in automatic mode, without people on board.

A subsequent mission with crew is expected to fly in the second quarter of 2018.

SpaceX is currently contracted to perform an average of four Dragon 2 missions to the ISS per year, three carrying cargo and one carrying crew.

"By also flying privately crewed missions, which NASA has encouraged, long-term costs to the government decline and more flight reliability history is gained, benefiting both government and private missions," SpaceX said.

SpaceX said it will conduct health and fitness tests of the two individuals who have expressed interest in a trip around moon. Initial training for the two will begin later this year.

"This presents an opportunity for humans to return to deep space for the first time in 45 years and they will travel faster and further into the solar system than any before them," SpaceX said in the statement.

"Other flight teams have also expressed strong interest and we expect more to follow," SpaceX said.