US President Barack Obama has said he is fully committed to the space agency, NASA, despite concerns over a replacement for the space shuttle programme, which is coming to an end.

During a visit to the Kennedy Space Centre at Cape Canaveral in Florida, Mr Obama said he understood workers' fears.

However, he insisted he wanted to see manned missions to Mars in the next 30 years.

‘By 2025 we expect new spacecraft designed for long journeys to allow us to begin the first ever crew missions beyond the moon into deep space,’ Mr Obama said.

‘So, we'll start by sending astronauts to an asteroid for the first time in history. By the mid-2030s, I believe we can send humans to orbit Mars and return them safely to earth, and a landing on Mars will follow.’

Mr Obama, who was accompanied by astronaut and moonwalker Buzz Aldrin, said a return to the moon surface should be attempted, but has set his goals further away in space.

His plan includes ramping up ‘robotic exploration of the solar system, including a probe of the sun's atmosphere, new scouting missions to Mars and other destinations, and an advanced telescope to follow Hubble.’

He added: ‘As president, I believe that space exploration is not a luxury, it's not an afterthought in America's quest for a brighter future. It is an essential part of that quest.’

Mr Obama said that the plan would create 2,500 jobs.