Obama has had to defend his commitment to the space agency in the politically important U.S. state after submitting a budget to Congress that would cancel a program to return U.S. astronauts to the moon.

Obama wants to refocus NASA efforts on technologies to prepare for human missions to other destinations in the solar system.

His budget would spend $6 billion over five years to turn over space transportation to commercial companies as well as billions of dollars on technology development and extending the life of the International Space Station.

"After years of underinvestment in new technology and unrealistic budgeting, the President's plan will unveil an ambitious plan for NASA that sets the agency on a reinvigorated path of space exploration," the White House said in a statement.

It said the investment in new technology would "help us travel from the Earth's cradle to our nearby Solar System neighborhood in a more effective and affordable way, thus laying the foundation to support journeys to the Moon, asteroids, and eventually to Mars."

The White House-sponsored conference will take place on April 15.

"The conference will focus on the goals and strategies in this new vision, the next steps, and the new technologies, new jobs, and new industries it will create," it said. "Conference topics will include the implications of the new strategy for Florida, the nation, and our ultimate activities in space."

Florida is a political "swing" state that tends to shift its support between Democrats and Republicans in presidential elections. In 2008 the state backed Obama, a Democrat, for the presidency over his Republican challenger, Senator John McCain.